Question

find the area. a = ?cm² area of a trapezoid $\frac{(b_1 + b_2)}{2}cdot h$ 3 cm 9 cm 21 cm

Explanation:

Step1: Identify the values of $b_1$, $b_2$ and $h$

$b_1 = 3$ cm, $b_2=21$ cm, $h = 9$ cm

Step2: Substitute values into the formula

$A=\frac{(b_1 + b_2)\cdot h}{2}=\frac{(3 + 21)\times9}{2}$

Step3: Calculate the sum in the numerator

$3+21 = 24$, so $A=\frac{24\times9}{2}$

Step4: Calculate the product in the numerator

$24\times9=216$, so $A=\frac{216}{2}$

Step5: Calculate the final result

$A = 108$

Answer:

$108$