Question

The base edge of the regular triangular pyramid is b=10 cm and altitude of the base hb ≈ 8.66 cm. The slant height of the pyramid is k=8 cm. Find:

Lateral area of the pyramid

Answer 1

`120^(2)`

i did rsm before

Answer 2

The lateral area of the pyramid is
`120\ cm^(2)`

Explanation:

we know that

The lateral area of the pyramid is equal to the area of its three triangular lateral faces

so

`LA=3[(1)/(2)(b)(k)]`

where

`b=10\ cm`

`k=8\ cm` ------> the slant height

substitute the values

`LA=3[(1)/(2)(10)(8)]=120\ cm^(2)`