The diameter of a circle is 18 cm. If the angle subtended at the centre of the circle is 125°, find the length of the major arc. ( Take π = 22/7 )
Source: JAMB · 2024
The diameter of a circle is 18 cm. If the angle subtended at the centre of the circle is 125°, find the length of the major arc.
( Take π = 22/7 )
Explanation
Radius = 18 ÷ 2 = 9 cm. The major arc uses the angle that is left over: 360° − 125° = 235°.
Arc = (235/360) × 2 × (22/7) × 9 = (235/360) × 56.57 = 36.93 cm.
Using 125° would give the minor arc, which is a tempting mistake.
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