Q. 2 E

# Sum of the three exterior angles of a triangle is __________A. two right anglesB. three right anglesC. one right angleD. four right angles

We know that an exterior angle of a triangle is equal to the sum of the interior opposite angles.

⇒ ∠A + B = external C

A + C = external B

C + B = external A

2A + 2 B + 2C = sum of the three external angles

2(A + B + C) = sum of the three external angles

We know that the sum of the angles of a triangle is 180°.

2× 180° = sum of the three external angles

Sum of the three external angles = 4 × 90°

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