Area of a Trapezoid - Examples, Exercises and Solutions

Formula for the area of a trapezoid:

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

We substitute the data into the formula and solve:

$\frac{9+12}{2}\times5=\frac{21}{2}\times5=\frac{105}{2}=52.5$

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



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

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

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

We substitute the given values into the formula:

(2.5+4)*6 =
6.5*6=
39/2 = 
19.5

The formula for the area of a trapezoid is:

We are given the following dimensions:

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

Substituting these values into the formula, we have:

First, add the lengths of the bases:

Now substitute back into the formula:

Calculate the multiplication:

Then multiply by the height:

Thus, the area of the trapezoid is 49 cm$^2$.

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 $h = 3$ cm.
One base $b_1 = 4$ cm.
The other base $b_2 = 7$ cm.

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

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

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

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

The area of the trapezoid is therefore $16.5$ cm².

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

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