Question

Question 1. Find the surface area of the square pyramid below.

Question 2. Find the surface area of the figure below.
Question 3. Find the surface area of the figure below.

Answer 1

see explanation

Explanation:

(1)

SA = area of square base + area of 4 congruent triangular faces

= (3.5 × 3.5) + (4 ×
`(1)/(2)` × 3.5 × 10 )

= 12.25 + 70

= 82.25 in²

(2)

SA = area of circular base + area of curved surface

[ area of curved surface = πrs, r is the radius and s the slant height ]

SA = π × 2² + π × 2 × 6 = 4π + 12π = 16π ≈ 50.27 m²

(3)

SA = area of circular base + area of curved surface

[ note diameter = 19, hence r = 9.5 ]

SA = π × 9.5² + π × 9.5 × 17 = 90.25π + 161.5π = 251.75π ≈ 790.90 cm²