What is the area of the shaded region in square cenimeters?

Question

The circumference of the circle is approximately 125.66 centimeters. The shaded region is 4/5 of the whole circle.

Answer 1

1. Use the equation for Circumference and solve for your radius

The equation for Circumference is C = 2(π )r,

where r = radius of the circle. Use 125.66 for the C value

2. Use your radius and the equation for area of a circle to find your TOTAL area

The equation for area of a circle is A = (π )r²

Use the radius from part 1

3 . Multiply that total area by (4/5) and that is your final answer.

I hope this helps. Please feel free to reach out if you'd like me to clarify anything :)

Answer 2

Hi Daniela L

Since the Circumference = ∏*diameter and radius is half of the diameter you can calculate the radius.

The area of a circle is ∏*(radius)² for the whole circle and according to the information, you need to know the area of 4/5 of the circle.

If I’ve interpreted your information correctly, the area you seek is 80% of the area of the circle.

With the given information the following substitution should help you with the calculations

Given the circumference 125.66 cm

Circumference = 125.66 = ∏*diameter

Solve for the diameter

125.66/∏ = diameter

diameter/2 = radius

Area = ∏*(radius)²

You need 80% of this number because 4/5 = 0.80

Can you continue from here?

I hope this helps.