Answer:
see explanation
Step-by-step explanation:
A
The area (A) of a circle is calculated as
A = πr² ( r is the radius )
Here diameter = 12 , then radius = 12 ÷ 2 = 6 , then
A = π × 6² = 3.14 × 36 = 113.04 m²
B
The circumference (C) of a circle is calculated as
C = 2πr ( r is the radius )
Here C = 28.26 , then
2πr = 28.26 ( divide both sides by 2π )
r = =
= 4.5 in
Answer:
Area of semicircle = 1/2(πr^2)
Area of quarter circle = 1/4(πr^2)
Step-by-step explanation:
The question is incomplete. You didn't provide the diagrams for the semicircle and quarter circle to evaluate the areas. I would explain how to find the area of a semicircle and quarter circle.
Area of a circle = πr^2
where r = radius and π = 3.14
If diameter (d) is given: d = 2r
To get radius, divide diameter by 2.
r = d/2
A semicircle is half of a circle.
Area of a semicircle is half the area of a circle.
Area of a semicircle = 1/2(πr^2)
A quarter circle is a quarter of a circle.
Area of a quarter circle is quarter of the area of a circle.
Area of a quarter circle = 1/4(πr^2)
Further explanation with diagram has been added as as an attachment.
