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

A) 220.5 mm^2

Step-by-step 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.

252 = 31.5 +

220.5 = lateral area of triangular pyramid

lateral area of triangular pyramid = 220.5 mm^2

maybe - definition of supplementary angles. im not sure. sorry

step-by-step explanation:

english, cause i can’t you