Right-Angled Trapezoid Area Practice Problems & Solutions

Master calculating the area of right trapezoids with step-by-step practice problems. Learn formulas, identify properties, and solve real-world geometry exercises.

📚Master Right-Angled Trapezoid Area Calculations
  • Apply the area formula: (base1 + base2) × height ÷ 2
  • Identify the height as the perpendicular side connecting right angles
  • Solve problems with given bases and height measurements
  • Calculate missing dimensions when area is provided
  • Recognize right-angled trapezoid properties and angle relationships
  • Work through multi-step word problems involving trapezoid areas

Understanding Area of a Trapezoid

Complete explanation with examples

Area of a right trapezoid

In order to calculate the area of a right-angled trapezoid, we will use the following formula:

Diagram of a right-angled trapezoid with the formula for calculating its area:  ( Base 1 + Base 2 ) × height (Base 1+Base 2)×height. The illustration highlights the two parallel bases, the height, and the application of the formula to find the area. Featured in a tutorial on calculating the area of trapezoids.


The formula for calculating the area of a right-angled trapezoid is the same as every trapezoid's area - the sum of the bases times the height divided by 2.

The leg connecting the 2 right angles is also the height of the trapezoid!

Detailed explanation

Practice Area of a Trapezoid

Test your knowledge with 21 quizzes

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

Examples with solutions for Area of a Trapezoid

Step-by-step solutions included
Exercise #1

Calculate the area of the trapezoid.

555141414666

Step-by-Step Solution

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

Note that we are only provided with one base and it is not possible to determine the size of the other base.

Therefore, the area cannot be calculated.

Answer:

Cannot be calculated.

Video Solution
Exercise #2

Calculate the area of the trapezoid.

666777121212555

Step-by-Step Solution

To find the area of the trapezoid, we would ideally use the formula:

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

where b1b_1 and b2b_2 are the lengths of the two parallel sides and hh is the height. However, the given information is incomplete for these purposes.

The numbers provided (66, 77, 1212, and 55) do not clearly designate which are the bases and what is the height. Without this information, the dimensions cannot be definitively identified, making it impossible to calculate the area accurately.

Thus, the problem, based on the given diagram and information, cannot be solved for the area of the trapezoid.

Therefore, the correct answer is: It cannot be calculated.

Answer:

It cannot be calculated.

Video Solution
Exercise #3

Calculate the area of the trapezoid.

555888333

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

Video Solution
Exercise #4

What is the area of the trapezoid ABCD?

999121212555AAABBBCCCDDDEEE

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

Video Solution
Exercise #5

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.

444888666BBBCCCDDDAAAEEE

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

Video Solution

Frequently Asked Questions

What is the formula for finding the area of a right-angled trapezoid?

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The area of a right-angled trapezoid is (base1 + base2) × height ÷ 2. This is the same formula used for all trapezoids, where you add the parallel bases, multiply by the height, and divide by 2.

How do you identify the height in a right-angled trapezoid?

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In a right-angled trapezoid, the height is the perpendicular side that connects the two right angles. This side is perpendicular to both parallel bases and represents the shortest distance between them.

What are the key properties of a right-angled trapezoid?

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A right-angled trapezoid has these properties: 1) Two angles equal to 90 degrees each, 2) The side connecting the right angles is the height, 3) All angles sum to 360 degrees, 4) The two non-right angles sum to 180 degrees.

How do you solve trapezoid area problems when the area is given?

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When the area is given, substitute known values into the formula and solve for the unknown. For example, if area = 25 and sum of bases = 10, then 25 = (10 × height) ÷ 2, so height = 5.

What's the difference between a right trapezoid and regular trapezoid area calculation?

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The area formula is identical for both types: (base1 + base2) × height ÷ 2. The difference is that in right trapezoids, the height is easier to identify as it's the side connecting the two right angles.

Can you calculate trapezoid area if you only know the angles and one side?

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No, you need at least the lengths of both parallel bases and the height to calculate the area. Knowing only angles and one side length is insufficient for area calculation using the standard formula.

What units should I use for trapezoid area answers?

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Area is always expressed in square units (units²). If the measurements are in centimeters, the area is in cm². If in meters, then m². Always match your area units to the square of your linear measurement units.

How do right-angled trapezoids appear in real-world applications?

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Right-angled trapezoids appear in architecture (roof designs, ramps), engineering (bridge supports), and landscaping (garden plots). Understanding their area calculation helps in material estimation and space planning.

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