Question

NEED ANSWER FAST

Which of the following shows a correct method to calculate the surface area of the cylinder?

cylinder with diameter labeled 2.8 feet and height labeled 4.2 feet

SA = 2π(2.8)2 + 2.8π(4.2) square feet
SA = 2π(1.4)2 + 2.8π(4.2) square feet
SA = 2π(2.8)2 + 1.4π(4.2) square feet
SA = 2π(1.4)2 + 1.4π(4.2) square feet

Answer 1

D is the correct answer

Answer 2

SA = [2π(1.4)² + 2.8π(4.2)] ft² (Answer B)

Explanation:

d = 2.8 ft; r = 1.4 ft

h = 4.2 ft

SA = area of 2 circular bases + lateral area

SA = 2πr² + 2πrh

SA = 2π(1.4)² + 2π(1.4)(4.2)

SA = 2π(1.4)² + 2.8π(4.2)