Question

Triangle DEF of the given figure is a right triangle with ∠E = 90°. What type of angles are ∠D and ∠F?

पर्याय

• They are equal angles

• They form a pair of adjacent angles

• They are complementary angles

• They are supplementary angles

Answer 1

They are complementary angles

Explanation:

In ΔDEF,

∠D + ∠E + ∠F = 180°  ......[Angle sum property of a triangle]

⇒ ∠D + 90° + ∠F = 180°  ......[∵ ∠E = 90°, given]

⇒ ∠D + ∠F = 180° – 90°

⇒ ∠D + ∠F = 90°

∴ ∠D and ∠F are complementary angles.