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Hi can someone please help me? :( im not sure where im going wrong. ty!!

"Find the area of the shaded regions below. Give your answer as a completely simplified exact value in terms of π (no approximations)."

Hi can someone please help me? :( im not sure where im going wrong. ty!! "Find-example-1
User RufatZZ
by
8.6k points

1 Answer

5 votes

The triangle ABC is a right angled triangle , right angled at C because it is the angle subtended by the diameter

Now OA = OB = OC = 4 cm (radii)

AB = OA + OB = 8 cm

By pythagoras theorem ,


AB^2 - BC^2 = AC^2


√(64 - 16) = AC

AC =4
\sqrt3

shade region area = area of semicircle - area of triangle

=
1/2 \pi r^2 - 1/2 × base × height

=1/2 × 16
\pi - 1/2 × 4 ×
4\sqrt3

=8
\pi - 8
\sqrt3

=8(
\pi - \sqrt3)

User Alex Stiff
by
7.8k points