A regular right pyramid has a square base with side length 16 cm and a height of 30 cm. Calculate the slant height and total surface area. (in approx)
Show answer & explanation
Correct answer: A
Explanation
Given:
Side of the square base = 16 cm
Height = 30 cm
By the formula:
Slant height l = √(h² + (a/2)²)
l = √(30² + 8²)
= √(900 + 64)
= √964
≈ 31.05 cm
Area of the base = 16² = 256
Perimeter of the base = 4 × 16 = 64
Lateral surface area = 1/2 × perimeter of the base × l
Lateral surface area = 1/2 × 64 × 31.05 = 993.6
Total surface area = Area of the base + lateral surface area
Total surface area = 256 + 993.6 = 1249.6
Slant height = 31.05 cm
Total surface area = 1249.6 cm²