find the diameter of 8.1 cm
Answers
Answered by
1
Answer:
The area of a circle with radius 4.05 is 51.53
Step-by-step explanation:
Formulae:
r = 4.05
d = 8.1
C = 25.5
A = πr2 = π(d
2
)2 A = C2
4π
π = 3.1415
A = area
C = circumference or perimeter
r = radius, d = diameter
Solution Steps:
Area of a circle in terms of radius:
Area = π·r2 = 3.14·4.052 = 51.53 square centimeters(*)
Area of a circle in terms of diameter:
Area = π·(d
2
)2 = 3.14·(8.1
2
)2 = 3.14·(4.05)2 = 51.53 square centimeters(*)
Area of a circle in terms of circumference:
Area = C2
4π
= 25.452
4π
= 647.7
(4·3.14)
= 647.7
12.56
= 51.53 square
Similar questions