Answer:
Step-by-step explanation:
The formula for the area of a circle is ...
A = πr^2
where the radius (r) is half the diameter. For a circle with a diameter of 20 units, the radius is 10 units and the circle area is ...
A = π·(10 units)^2 = 100π units^2 ≈ 314.16 square units
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When there are 20 congruent sectors, each sector has an area of 1/20 of the circle area, so
sector area = (1/20)·100π unit^2 = 5π units^2 ≈ 15.7 square units