Question

Um quadrado de lado2,5 tem 6,25 cm de área

Answer 1

a) Verdadeiro.

$l=2.5\ cm^2\ \therefore\ \boxed{A=l^2}=2.5^2\ \therefore\ \boxed{A=6.25\ cm^2}$

b) Verdadeiro.

$b=3\ cm,\ h=1.6\ cm\ \therefore\ \boxed{A=bh}=3(1.6)\ \therefore\ \boxed{A=4.8\ cm^2}$

c) Verdadeiro.

$b=3\ cm,\ h=1.6\ cm\ \therefore\ \boxed{A=\dfrac{bh}{2}}=\dfrac{3(1.6)}{2}\ \therefore\ \boxed{A=2.4\ cm^2}$

d) Verdadeiro.

$D=3\ cm,\ d=1.6\ cm\ \therefore\ \boxed{A=\dfrac{Dd}{2}}=\dfrac{3(1.6)}{2}\ \therefore\ \boxed{A=2.4\ cm^2}$

e) Falso.

$B=3\ cm,\ b=1.6\ cm,\ h=2\ cm\ \therefore\\\\ \boxed{A=\dfrac{h(B+b)}{2}}=\dfrac{2(3+1.6)}{2}\ \therefore\ \boxed{A=4.6\ cm^2}$