Question

Em um trapézio, a base maior mede 24 cm e sua altura, 16,5 cm.

Qual sera sua area, se a base menor for 3/4 da base maior?

Answer 1

Base maior: 24 cm
Base menor: 3/4 de 24 = 18 cm
Altura: 16,5 cm

$A=\frac{B+b}{2}*h\\ \\ A=\frac{24+18}{2}*16,5=346,5 \ cm^2$

Answer 2

$S=\dfrac{(B+b)\cdot(h)}{2}$

$B=24$

$h=16,5$

$b=\dfrac{3}{4}\cdot(B)~~\Rightarrow~~b=\dfrac{3}{4}\cdot24~~\Rightarrow~~b=18$

$S=\dfrac{(24+18)\cdot16,5}{2}~~\Rightarrow~~S=\dfrac{42\cdot16,5}{2}~~\Rightarrow~~S=21\cdot16,5$

$S=346,5~\text{cm}^2$.