Show that in a circle of radius r, a sector with a central angle of θ radians has an area 1/2*r^2*θ.?
Show that in a circle of radius r, a sector with a central angle of θ radians has an area 1/2*r^2*θ. Take θ between 0 and 2π. Hint: the area of the circle is π*r^2
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Verified answer
Hi Julia R,
Notice that an entire circle has an angle of 2π.
The fraction of the sector we are working on with regards to the entire circle is θ/2π
The area of an entire circle is πr^2
The area of the sector which is θ/2π of an entire circle is:
(θ/2π) x (πr^2)
= (θ/2) x r^2
= (1/2) x θ x r^2
= (1/2)r^2 θ
Cheers.