Examples with solutions for Area of a Trapezoid: Applying the formula

Exercise #1

What is the area of the trapezoid in the figure?

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Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the given information relevant to the trapezoid.
  • Step 2: Apply the appropriate formula for the area of a trapezoid.
  • Step 3: Perform the necessary calculations to find the area.

Now, let's work through each step:
Step 1: The problem gives us two bases, b1=6 b_1 = 6 cm and b2=12 b_2 = 12 cm, and a height h=4 h = 4 cm.
Step 2: We'll use the formula for the area of a trapezoid: A=12(b1+b2)h A = \frac{1}{2} \cdot (b_1 + b_2) \cdot h
Step 3: Substituting in the given values: A=12(6+12)4=12184=722=36 cm2 A = \frac{1}{2} \cdot (6 + 12) \cdot 4 = \frac{1}{2} \cdot 18 \cdot 4 = \frac{72}{2} = 36 \text{ cm}^2

Therefore, the solution to the problem is 36 36 cm².

Answer

36 36 cm².

Exercise #2

Given the following trapezoid:

AAABBBCCCDDD7115

Calculate the area of the trapezoid ABCD.

Video Solution

Step-by-Step Solution

To calculate the area of the trapezoid ABCD, we will follow these steps:

Given:

  • Base AB=7 AB = 7
  • Base CD=11 CD = 11
  • Height =5 = 5

Apply the trapezoid area formula:

The formula for the area of a trapezoid is:

A=12×(Base1+Base2)×Height A = \frac{1}{2} \times (\text{Base}_1 + \text{Base}_2) \times \text{Height}

Substitute the values into the formula:

A=12×(7+11)×5 A = \frac{1}{2} \times (7 + 11) \times 5

Simplify the expression:

A=12×18×5 A = \frac{1}{2} \times 18 \times 5

Calculate:

A=12×90 A = \frac{1}{2} \times 90

Finally, compute the area:

A=45 A = 45

Thus, the area of trapezoid ABCD is 45 45 .

Answer

45

Exercise #3

Given the following trapezoid:

AAABBBCCCDDD5104

Calculate the area of the trapezoid ABCD.

Video Solution

Step-by-Step Solution

To solve this problem, we'll calculate the area of trapezoid ABCD using the appropriate formula.

The formula for the area A A of a trapezoid is given by:

A=12×(Base1+Base2)×Height A = \frac{1}{2} \times (\text{Base}_1 + \text{Base}_2) \times \text{Height}

Substituting the given values into the formula, we have:

A=12×(5+10)×4 A = \frac{1}{2} \times (5 + 10) \times 4

First, calculate the sum of the bases:

5+10=15 5 + 10 = 15

Multiply by the height, and then take half:

A=12×15×4=12×60=30 A = \frac{1}{2} \times 15 \times 4 = \frac{1}{2} \times 60 = 30

Therefore, the area of the trapezoid ABCD is 30 square units.

Answer

30

Exercise #4

Given the following trapezoid:

AAABBBCCCDDD584

Calculate the area of the trapezoid ABCD.

Video Solution

Step-by-Step Solution

To solve this problem, we follow these steps:

  • Step 1: Identify the given dimensions of the trapezoid.
  • Step 2: Use the formula for the area of a trapezoid.
  • Step 3: Substitute the given values into the formula and calculate the area.

Now, let's work through these steps:

Step 1: We know from the problem that trapezoid ABCD has bases AB=5 AB = 5 and CD=8 CD = 8 , with a height of AD=4 AD = 4 .

Step 2: The formula for the area of a trapezoid is:
A=12×(b1+b2)×h A = \frac{1}{2} \times (b_1 + b_2) \times h

Step 3: Plugging in the values:
A=12×(5+8)×4=12×13×4=522=26 A = \frac{1}{2} \times (5 + 8) \times 4 = \frac{1}{2} \times 13 \times 4 = \frac{52}{2} = 26

Therefore, the area of the trapezoid ABCD is 26 26 .

Answer

26

Exercise #5

What is the area of the trapezoid ABCD?

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Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Identify the given measurements: the lengths of the parallel sides (bases) and the height.
  • Use the trapezoid area formula to calculate the area.
  • Perform the necessary arithmetic to find the numerical answer.

Now, let's work through each step:
Step 1: The given measurements are Base1=9 \text{Base}_1 = 9 , Base2=12 \text{Base}_2 = 12 , and the height = 5.
Step 2: The formula for the area of a trapezoid is Area=12×(Base1+Base2)×Height \text{Area} = \frac{1}{2} \times (\text{Base}_1 + \text{Base}_2) \times \text{Height} .
Step 3: Substituting the numbers into the formula, we have:
Area=12×(9+12)×5 \text{Area} = \frac{1}{2} \times (9 + 12) \times 5

Calculating inside the parentheses first:
9+12=21 9 + 12 = 21

Then multiply by the height:
21×5=105 21 \times 5 = 105

Finally, multiply by one-half:
12×105=52.5 \frac{1}{2} \times 105 = 52.5

Therefore, the area of trapezoid ABCD ABCD is 52.5 52.5 .

Answer

52.5

Exercise #6

What is the area of the trapezoid in the figure?

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Video Solution

Step-by-Step Solution

To solve this problem, we'll compute the area of the trapezoid using the given dimensions and the area formula:

  • Step 1: Identify the given dimensions:
    • Base b1=10 b_1 = 10 cm
    • Base b2=6.5 b_2 = 6.5 cm
    • Height h=4 h = 4 cm
  • Step 2: Use the trapezoid area formula:
  • The formula for the area of a trapezoid is A=12(b1+b2)h A = \frac{1}{2}(b_1 + b_2)h .

  • Step 3: Substitute the given values into the formula:
  • A=12(10+6.5)×4 A = \frac{1}{2}(10 + 6.5) \times 4

  • Step 4: Calculate the area:
  • First, calculate the sum of the bases: 10+6.5=16.5 10 + 6.5 = 16.5 .

    Next, multiply by the height: 16.5×4=66 16.5 \times 4 = 66 .

    Finally, divide by 2 to get the area: 662=33\frac{66}{2} = 33 cm².

Therefore, the area of the trapezoid is 33 33 cm².

Answer

33 33 cm².

Exercise #7

What is the area of the trapezoid in the diagram below?

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Video Solution

Step-by-Step Solution

To determine the area of the trapezoid, we will follow these steps:

  • Step 1: Identify the provided dimensions of the trapezoid.
  • Step 2: Apply the formula for the area of a trapezoid.
  • Step 3: Perform the arithmetic to calculate the area.

Let's proceed through these steps:

Step 1: Identify the dimensions
The given dimensions from the diagram are:
Height h=3 h = 3 cm.
One base b1=4 b_1 = 4 cm.
The other base b2=7 b_2 = 7 cm.

Step 2: Apply the area formula
To find the area A A of the trapezoid, use the formula:
A=12×(b1+b2)×h A = \frac{1}{2} \times (b_1 + b_2) \times h

Step 3: Calculation
Substituting the known values into the formula:
A=12×(4+7)×3 A = \frac{1}{2} \times (4 + 7) \times 3

Simplify the expression:
A=12×11×3 A = \frac{1}{2} \times 11 \times 3

Calculate the result:
A=12×33=332=16.5 A = \frac{1}{2} \times 33 = \frac{33}{2} = 16.5 cm²

The area of the trapezoid is therefore 16.5 16.5 cm².

Given the choices, this corresponds to choice : 16.5 16.5 cm².

Therefore, the correct solution to the problem is 16.5 16.5 cm².

Answer

16.5 16.5 cm²

Exercise #8

The trapezoid ABCD is shown below.

Base AB = 6 cm

Base DC = 10 cm

Height (h) = 5 cm

Calculate the area of the trapezoid.

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Video Solution

Step-by-Step Solution

First, we need to remind ourselves of how to work out the area of a trapezoid:

(Base+Base)h2=Area \frac{(Base+Base)\cdot h}{2}=Area

Now let's substitute the given data into the formula:

(10+6)*5 =
2

Let's start with the upper part of the equation:

16*5 = 80

80/2 = 40

Answer

40 cm²

Exercise #9

What is the area of the trapezoid in the figure?

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Video Solution

Step-by-Step Solution

We use the following formula to calculate the area of a trapezoid: (base+base) multiplied by the height divided by 2:

(AB+DC)×BE2 \frac{(AB+DC)\times BE}{2}

(7+15)×22=22×22=442=22 \frac{(7+15)\times2}{2}=\frac{22\times2}{2}=\frac{44}{2}=22

Answer

22 22 cm².

Exercise #10

Given the following trapezoid:

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Calculate the area of the trapezoid ABCD.

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Recall the formula for the area of a trapezoid.
  • Step 2: Substitute the given values into the formula.
  • Step 3: Calculate the area using arithmetic operations.

Let's work through each step:
Step 1: The formula for the area of a trapezoid is given by:
Area=12×(Base1+Base2)×Height \text{Area} = \frac{1}{2} \times (\text{Base}_1 + \text{Base}_2) \times \text{Height}
Step 2: Plug in the values: Base1=AB=6\text{Base}_1 = AB = 6, Base2=CD=8\text{Base}_2 = CD = 8, and the height AD=3AD = 3.
Area=12×(6+8)×3 \text{Area} = \frac{1}{2} \times (6 + 8) \times 3
Step 3: Perform the calculations:
Area=12×14×3=12×42=21 \text{Area} = \frac{1}{2} \times 14 \times 3 = \frac{1}{2} \times 42 = 21

Therefore, the area of trapezoid ABCDABCD is 2121.

Answer

21

Exercise #11

Given the following trapezoid:

AAABBBCCCDDD795

Calculate the area of the trapezoid ABCD.

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the lengths of the trapezoid's bases: AB=7 AB = 7 and CD=9 CD = 9 .
  • Step 2: Identify the height of the trapezoid: AD=5 AD = 5 .
  • Step 3: Apply the trapezoid area formula: A=12×(b1+b2)×h A = \frac{1}{2} \times (b_1 + b_2) \times h .
  • Step 4: Calculate the area using the values from Steps 1 and 2.

Now, let us work through each step:
Step 1: The length of base AB AB is (b1=7)(b_1 = 7) units, and the length of base CD CD is (b2=9)(b_2 = 9) units.
Step 2: The height AD AD is (h=5)(h = 5) units.

Step 3: Substitute the known values into the formula for the area of a trapezoid:
A=12×(7+9)×5 A = \frac{1}{2} \times (7 + 9) \times 5

Step 4: Calculate the results:
A=12×16×5=12×80=40 A = \frac{1}{2} \times 16 \times 5 = \frac{1}{2} \times 80 = 40

Therefore, the area of trapezoid ABCD is 40\mathbf{40} square units.

Answer

40

Exercise #12

The trapezoid ABCD is shown below.

AB = 5 cm

DC = 9 cm

Height (h) = 7 cm

Calculate the area of the trapezoid.

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Video Solution

Step-by-Step Solution

The formula for the area of a trapezoid is:

Area=12×(Base1+Base2)×Height \text{Area} = \frac{1}{2} \times (\text{Base}_1 + \text{Base}_2) \times \text{Height}

We are given the following dimensions:

  • Base AB=5AB = 5 cm
  • Base DC=9DC = 9 cm
  • Height h=7h = 7 cm

Substituting these values into the formula, we have:

Area=12×(5+9)×7 \text{Area} = \frac{1}{2} \times (5 + 9) \times 7

First, add the lengths of the bases:

5+9=14 5 + 9 = 14

Now substitute back into the formula:

Area=12×14×7 \text{Area} = \frac{1}{2} \times 14 \times 7

Calculate the multiplication:

12×14=7 \frac{1}{2} \times 14 = 7

Then multiply by the height:

7×7=49 7 \times 7 = 49

Thus, the area of the trapezoid is 49 cm2^2.

Answer

49 cm

Exercise #13

Calculate the area of the trapezoid.

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Video Solution

Step-by-Step Solution

To solve this problem, we'll calculate the area of the trapezoid using the standard formula:

  • Step 1: Identify the given dimensions:
  • Shorter base b1=5 b_1 = 5 .
  • Longer base b2=8 b_2 = 8 .
  • Height h=3 h = 3 .

Step 2: We apply the trapezoid area formula, which is:

A=12×(b1+b2)×h A = \frac{1}{2} \times (b_1 + b_2) \times h .

Step 3: Substitute the given values into the formula:

A=12×(5+8)×3 A = \frac{1}{2} \times (5 + 8) \times 3 .

Step 4: Perform the calculations:

A=12×13×3 A = \frac{1}{2} \times 13 \times 3 .

A=12×39 A = \frac{1}{2} \times 39 .

A=19.5 A = 19.5 or 1912 19 \frac{1}{2} .

The area of the trapezoid is 1912 19 \frac{1}{2} .

Answer

19 1/2

Exercise #14

The trapezoid ABCD is shown below.

The height of ABCD is 6 cm.

The base BC is equal to 4 cm.

The base AD is equal to 8 cm.

Calculate the area of trapezoid ABCD.

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Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the given information
  • Step 2: Apply the appropriate formula
  • Step 3: Perform the necessary calculations

Now, let's work through each step:

Step 1: The problem gives us the height of the trapezoid as 6cm6 \, \text{cm}, base BC as 4cm4 \, \text{cm} and base AD as 8cm8 \, \text{cm}.

Step 2: We'll use the formula for the area of a trapezoid:

A=12×(base1+base2)×height A = \frac{1}{2} \times (\text{base}_1 + \text{base}_2) \times \text{height}

Step 3: Substituting the given values into the formula:

A=12×(4+8)×6 A = \frac{1}{2} \times (4 + 8) \times 6

Calculating further,

A=12×12×6 A = \frac{1}{2} \times 12 \times 6

A=12×72 A = \frac{1}{2} \times 72

A=36cm2 A = 36 \, \text{cm}^2

Therefore, the area of the trapezoid ABCD is 36cm236 \, \text{cm}^2.

Answer

36

Exercise #15

Given the trapezoid:

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What is the area?

Video Solution

Step-by-Step Solution

Formula for the area of a trapezoid:

(base+base)2×altura \frac{(base+base)}{2}\times altura

We substitute the data into the formula and solve:

9+122×5=212×5=1052=52.5 \frac{9+12}{2}\times5=\frac{21}{2}\times5=\frac{105}{2}=52.5

Answer

52.5

Exercise #16

What is the area of the trapezoid in the diagram?

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Video Solution

Step-by-Step Solution

To find the area of the trapezoid, we will follow these steps:

  • Step 1: Identify the given dimensions of the trapezoid.
  • Step 2: Apply the area formula for a trapezoid using these dimensions.
  • Step 3: Perform the calculation to determine the area.

Let's work through each step more clearly:
Step 1: From the problem, we identify that the trapezoid has one base b1=13b_1 = 13 units, another base b2=8b_2 = 8 units, and its height h=5h = 5 units.
Step 2: The formula for the area of a trapezoid is:

A=12×(b1+b2)×h A = \frac{1}{2} \times (b_1 + b_2) \times h

Step 3: Substitute the values into the formula:

A=12×(13+8)×5 A = \frac{1}{2} \times (13 + 8) \times 5

A=12×21×5 A = \frac{1}{2} \times 21 \times 5

A=12×105 A = \frac{1}{2} \times 105

A=52.5units2 A = 52.5 \, \text{units}^2

Therefore, the area of the trapezoid is 52.5units2 52.5 \, \text{units}^2 .

Answer

52.5 52.5 cm²

Exercise #17

The trapezoid ABCD is shown below.

AB = 2.5 cm

DC = 4 cm

Height (h) = 6 cm

Calculate the area of the trapezoid.

2.52.52.5444h=6h=6h=6AAABBBCCCDDD

Video Solution

Step-by-Step Solution

First, let's remind ourselves of the formula for the area of a trapezoid:

A=(Base + Base) h2 A=\frac{\left(Base\text{ }+\text{ Base}\right)\text{ h}}{2}

We substitute the given values into the formula:

(2.5+4)*6 =
6.5*6=
39/2 = 
19.5

Answer

1912 19\frac{1}{2}

Exercise #18

Given an isosceles trapezoid

What is your area?

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Video Solution

Step-by-Step Solution

For the trapezoid, we recognize that to calculate the area, we typically need both base lengths and the height. The area formula for a trapezoid is A=12×(b1+b2)×h A = \frac{1}{2} \times (b_1 + b_2) \times h , but we lack the values of the bases b1 b_1 and b2 b_2 . Thus, with given only the leg lengths as 4 units and height as 3 units, and without base lengths, calculation of area is impossible.

Therefore, the solution is that it is not possible to calculate the area with the provided information.

Answer

It is not possible to calculate

Exercise #19

What is the area of the trapezoid in the figure?

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Video Solution

Step-by-Step Solution

The area of a trapezoid is calculated using the formula:

Area=12×(Base1+Base2)×Height \text{Area} = \frac{1}{2} \times (\text{Base}_{1} + \text{Base}_{2}) \times \text{Height}

Given:

  • Base1=AB=12\text{Base}_{1} = AB = 12 units
  • Base2=CD=6\text{Base}_{2} = CD = 6 units
  • Height=h=4\text{Height} = h = 4 units

Plug these values into the formula:

Area=12×(12+6)×4 \text{Area} = \frac{1}{2} \times (12 + 6) \times 4

Calculate the sum of the bases:

12+6=18 12 + 6 = 18

Multiply by the height and divide by 2:

Area=12×18×4 \text{Area} = \frac{1}{2} \times 18 \times 4

Area=36 \text{Area} = 36 square units

Therefore, the area of the trapezoid is 36\mathbf{36} cm².

Answer

36 36 cm².

Exercise #20

What is the area of the trapezoid in the figure?

222999777AAABBBCCCDDD

Video Solution

Step-by-Step Solution

We use the formula: (base + base) multiplied by height divided by 2:

S=(AB+DC)×h2 S=\frac{(AB+DC)\times h}{2}

Keep in mind that AD is the height of a trapezoid:

We insert the existing data into the formula:

S=(2+9)×72 S=\frac{(2+9)\times7}{2}

S=11×72=772=38.5 S=\frac{11\times7}{2}=\frac{77}{2}=38.5

Answer

38.5 38.5 cm².