Theory question 103
Mensuration of Plane ShapesA chord subtends an angle of 72° at the centre of a circle of radius 24.5m. Calculate the perimeter of the minor segment. [Take π = 22/7]
Show the model answer
Model answer
Chord = 2r sin(72°/2) = 49 sin 36° ≈ 28.80 m
Minor arc = 72/360 × 2 × (22/7) × 24.5 = 30.8 m
Perimeter = 28.80 + 30.80 ≈ 59.6 m
Explanation
The minor segment is bounded by the chord and the minor arc.