<u>Part 1)</u> A 20° sector in a circle has an area of 21.5π yd².
What is the area of the circle?
we know that
the area of a circle represent a sector of
degrees
so by proportion
therefore
<u>the answer part 1) is</u>
The area of the circle is 
<u>Part 2)</u> What is the area of a sector with a central angle of 3π/5 radians and a diameter of 21.2 cm?
we know that
the area of the circle is equal to

where
r is the radius of the circle
in this problem we have

<u>Find the area of the circle</u>



<u>Find the area of the sector</u>
we know that the area of the circle represent a sector of
radians
by proportion
therefore
<u>the answer part 2) is</u>
the area of the sector is
