SOLUTION: A dart board has a diameter of 40 cm and is divided into 20 congruent sectors. What is the area of one of the sectors?. please help me answer this

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Question 997072: A dart board has a diameter of 40 cm and is divided into 20 congruent
sectors. What is the area of one of the sectors?. please help me answer this
Answer by Theo(13342) (Show Source):
You can put this solution on YOUR website!
the radius is equal to half the diameter = 20 cm.
the area of the circle formed is equal to pi * 20^2 = 400 * pi
there are 20 sectors that are all congruent to each other, so the area of each individual sector is 400 * pi / 20 = 20 * pi.

you can also calculate it another way.
if there are 20 congruent sectors, then each sector has a central angle of 360 / 20 = 18.
the area of the sector is equal to the central angle of the sector divided by 360 * the area of the circle.
18/360 * 400 * pi = 1/20 * 400 * pi = 400 / 20 * pi = 20 * pi.