AP State Syllabus AP Board 7th Class Maths Solutions Chapter 4 Lines and Angles Ex 2 Textbook Questions and Answers.

## AP State Syllabus 7th Class Maths Solutions 4th Lesson Lines and Angles Exercise 2

Question 1.

Which of the following pairs of angles are complementary?

Solution:

In fig (i) 110° – 30° = 140° ≠ 90. Hence they are not complementary.

In fig (ii) 90° + 90° = 180 ≠ 90°. Hence they are not complementary.

In fig (iii) 80° + 10° = 90° = 90. Hence they are complementary.

Question 2.

Find the complements of the given angles. Find the complementary angles of the following.

(i) 25°

(ii) 40°

(iii) 89°

(iv) 55°

Solution:

i) Complementary angle of 25° = 90° – 25° = 65°

ii) Complementary angle of 40° = 90° – 40° = 50°

ill) Complementary angle of 89° = 90° – 89° = 1°

iv) Complementary angle of 55° = 90° – 55 = 35°

Question 3.

Two angles are complement to each other and are also equal. Find them.

Solution:

Let the angle be x°

Then Its complement = (900_ x°)

By problem, x° = 90° – x°

x° + x°= 90°

2x = 90°

x = \(\frac{90^{\circ}}{2}\)

x = 45°

Question 4.

Manasa says, “Each angle in any pair of complementary angles is always acute”. Do

Solution:

Yes. Each angle ¡n any pair of complementary angles is always acute.

As sum of two angles is 90°, each of the angle must be less than 90°.