Mensuration Practice Test 5

Area of the triangle

a = 65 m b = 75 m c = 80 ma = 65 m b = 75 m c = 80 m
S = $\frac{\mathit{a}+\mathit{b}+\mathit{c}}{2}$ = $\frac{65+75+80}{2}$
= $\frac{220}{2}$ = 110
A = $\sqrt{\mathit{S}\left(\mathit{S}-\mathit{a}\right)\left(\mathit{S}-\mathit{b}\right)\left(\mathit{S}-\mathit{c}\right)}$
= $\sqrt{110\left(110-65\right)\left(110-75\right)\left(110-80\right)}$
= $\sqrt{110\times 35\times 45\times 30}$
=
= 2 × 5 × 5 × 3 $\sqrt{1\times 17\times 3}$
= $150\sqrt{231}$
= 150 ×15.19
= 2,279.8
= 2,280 ${\mathit{m}}^2$