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Question
In ∆PQR, ∠P = 70° and ∠R = 30°. Which side of this triangle is the longest? Give reason for your answer.
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Solution
Given, in ΔPQR, ∠P = 70° and ∠R = 30°.
We know that, sum of all the angles of a triangle is 180°.
∠P + ∠Q + ∠R = 180°
∴ ∠Q = 180° – (70° + 30°)
= 80°
We know that here ∠Q is longest, so side PR is longest ...[∴ Since in a triangle, the side opposite to the largest angle is the longest]
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