A segment of a circle has a 120 arc and a chord of 8 √3 in. Find the area of the segment.
Solution:
Here the area of segment = Area of the sector - Area of triangle
Consider the triangle from the figure to determine the radius.
Since the two right triangles have the same radii, a common side and the same 90° angle, by cpctc they are congruent.
Thus BM = AM = 4√3
From the definition of trigonometric ratios,
We know that cos 30° = adjacent /hypotenuse
√3/2 = 4√3/r
r = 4√3/√3/2
r = 8 units2
Area of a Sector of Circle = (θ/360º) × πr2 unit2
= (120º/360º) × π × 82
= 1/3 × 3.14 × 64
Area of the sector = 66.98 unit2
Area of triangle = ½ × ab × Sin C
Where a and b are the two side lengths and C is the angle included between them.
Here radii are the two sides and 120° is the angle between them.
Thus the area of the triangle = ½ × 64 × Sin 120°
=32× √3/2 = 16√3
Area of the triangle = 27.71 unit2
Area of the segment = Area of the sector - Area of triangle
Substituting the values
= 66.98 - 27.71
= 39.27 unit2
Therefore, the area of the segment is 39.27 unit2.
A segment of a circle has a 120 arc and a chord of 8 √3 in. Find the area of the segment.
Summary:
A segment of a circle has a 120 arc and a chord of 8 √3 in. The area of the segment is 39.27 unit2.
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