Question

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

Answer 1

Answer:

see explanation

Step-by-step explanation:

(1)

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

     = (3.5 × 3.5) + (4 × $\frac{1}{2}$ × 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

Answer 2

95.0cm is the answer of this