Triangle DEF of Fig. 6.6 is a right triangle with ∠E = 90°. What type of angles are ∠D and ∠F?
a. They are equal angles
b. They form a pair of adjacent angles
c. They are complementary angles
d. They are supplementary angles

Solution:

Given, DEF is a right triangle with ∠E = 90°.

We have to find the type of ∠D and ∠F.

Angle sum property of a triangle states that the sum of all three interior angles of a triangle is always equal to 180 degrees.

By angle sum property,

∠D + ∠E + ∠F = 180

∠D + 90 + ∠F = 180

∠D + ∠F = 180 - 90

∠D + ∠F = 90

When the sum of the measures of two angles is equal to 90 degrees, then the angles are called complementary angles.

Therefore, ∠D and ∠F are complementary angles.

✦ Try This: Can a triangle have two obtuse angles. Justify your answer

☛ Also Check: NCERT Solutions for Class 7 Maths Chapter 6

NCERT Exemplar Class 7 Maths Chapter 6 Problem 2

Triangle DEF of Fig. 6.6 is a right triangle with ∠E = 90°. What type of angles are ∠D and ∠F? a. They are equal angles, b. They form a pair of adjacent angles, c. They are complementary angles, d. They are supplementary angles

Summary:

Triangle DEF of Fig. 6.6 is a right triangle with ∠E = 90°. ∠D and ∠F are complementary angles

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