CAT 2018 Question Paper | CAT Verbal Ability Slot 2
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10 months ago
Question :
A chord of length 5 cm subtends an angle of 60° at the centre of a circle. The length, in cm, of a chord that subtends an angle of 120° at the centre of the same circle is
Option B
is the correct answer.
Explanatory Answer
Given that a chord of length 5 cm subtends an angle of 60° at the centre of a circle.
We have to find the length of a chord that subtends an angle of 120° at the centre of the same
circle
sin 60° = BC/OB
⟹ √3/2 = BC/5
⟹ BC = 5√3/2 and AC = 5√3/2
So AB = 5√3/2 + 5√3/2= 5√3
The length of a chord that subtends an angle of 120° at the centre of the same circle is 5√3
