A regular right triangular pyramid has base side = 10 cm, and slant height = 13 cm. Find the total surface area if all slant heights are equal and the base is equilateral.
Show answer & explanation
Correct answer: A
Explanation
Area of the base = (√3 / 4) × 10²
= 25√3 sq cm
Area of the three lateral triangles = 3 × (1/2 × 10 × 13)
= 195 sq cm
Total surface area = 195 + 25√3
= 195 + 43.3
= 238.3 sq cm