Question

Find the surface area of the triangular pyramid. The side lengths of the base are equal.

Answer 1

133.5 cm²

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:

`A=(b\cdot h)/(2)`

b - base

h - height

Substitute:

`A_1=((10)(6))/(2)=(60)/(2)=30\ cm^2`

`A_2=((10)(8.7))/(2)=(87)/(2)=43.5\ cm^2`

`S.A.=3A_1+A_2\\\\S.A.=3(30)+43.5=90+43.5=133.5\ cm^2`