Answer:
133.5 cm²
Step-by-step explanation:
We have
three triangles with the base b = 10cm and the height h₁ = 6cm
one triangle with the base b = 10cm and the height h₂ = 8.7cm.
The formula of an area of a triangle:
[tex]A=\dfrac{b\cdot h}{2}[/tex]
b - base
h - height
Substitute:
[tex]A_1=\dfrac{(10)(6)}{2}=\dfrac{60}{2}=30\ cm^2[/tex]
[tex]A_2=\dfrac{(10)(8.7)}{2}=\dfrac{87}{2}=43.5\ cm^2[/tex]
[tex]S.A.=3A_1+A_2\\\\S.A.=3(30)+43.5=90+43.5=133.5\ cm^2[/tex]
