A chord subtends an anle of 9°at the centre of a circle who chord is 20 cm. Compute the area of the correspoding major segmen of the circle.
Answers
A chord subtends an angle of 90°at the centre of a circle whose chord is 20 cm. Compute the area of the corresponding major segment of the circle.
Point to note:
Area of the sector = θ/360 × π × r²
Base and height of the triangle formed will be = radius of the circle
Area of the minor segment = area of the sector – area of the triangle formed
Area of the major segment = area of the circle – area of the minor segment
Now,
Radius of circle = r = 20 cm and
Angle subtended = θ = 90°
Area of the sector = θ/360 × π × r² = 90/360 × 22/7 × 202
Or, Area of the sector = 314.2 cm2
Area of the triangle = ½ × base × height
= ½ × 20 × 20 = 200 cm²
Area of the minor segment = 314.2 – 200 = 114.2 cm²
Area of the circle = π × r²
Area of the major segment = π × r² – 114.2 = 1142 .94 cm².
So, the area of the corresponding major segment of the circle = 1142 .94 cm²