Question

A regular triangular pyramid has a base area of 31.5 mm2 and a surface area of

252 mm2. What is the lateral area of the regular triangular pyramid?


A. 220.5 mm2

B. 126 mm2

C. 283.5 mm2

D. 127.75 mm2

Answer 1

A) 220.5 mm^2

Explanation:

Explanation:-

Given A regular triangular pyramid has a base of area is 31.5mm^2

and also given surface area of triangular pyramid is 252 mm ^2

by using formula

surface area of regular triangular pyramid = base of area + half of lateral surface.

`surface area = area of the pyramid X (1)/(2) lateral surface`

252 = 31.5 +
`(1)/(2) lateral surface`

`252-31.5= (1)/(2) lateral surface`

220.5 = lateral area of triangular pyramid

lateral area of triangular pyramid = 220.5 mm^2