Answer:
13. 169π ft²
16. 34π mm
17. 12π in
18. 441π m²
Step-by-step explanation:
Circumference of a circle is calculated as follows:
C = 2π*r
Area of a circle is calculated as follows:
A = π*r²
where <em>r</em> is the radius of the circle
13. circumference of the circle: 26π ft
Then, its radius is:
26π = 2π*r
r = 26π/(2π) = 13 ft
A = π*13² = 169π ft²
16. area of the circle: 289π mm²
Then, its radius is:
289π = π*r²
r = √289
r = 17 mm
C = 2π*17 = 34π mm
17. area of the circle: 113.1 in²
Then, its radius is:
113.1 = π*r²
r = √(113.1/π)
r = 6 in
C = 2π*6 = 12π in
18. circumference of the circle: 131.95 m
Then, its radius is:
131.95 = 2π*r
r = 131.95/(2π)
r = 21 m
A = π*21² = 441π m²
