Circumference 7823

The bases are 9 cm and 5 cm long in a rectangular trapezoid. The length of the shorter arm is 3 cm. Calculate its circumference and area.

Correct answer:

o =  22 cm
S =  21 cm²

Step-by-step explanation:

$$\begin{gathered} a=9\text{cm} \\ c=5\text{cm} \\ d=3\text{cm} \\ x=a-c=9-5=4\text{cm} \\ b=\sqrt{x^2+d^2}=\sqrt{4^2+3^2}=5\text{cm} \\ o=a+b+c+d=9+5+5+3=22\text{cm} \end{gathered}$$

$S=\frac{a+c}{2}\cdot d=\frac{9+5}{2}\cdot 3=21{\text{cm}}^2$

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