Question

Find angle x in each figure​

Answer 1

Answer:

(i) 40°

(ii) 90°

(iv) 40°

(v) 45°

(vii) 60°

(viii) 55°

Step-by-step explanation:

Answer 2

Given :

(i) 40°

(ii) 45°

(iv) 100°

(v) x

(vii) 120°

(viii) 110°

To find :

• the value of x

Solution :

⇒ Let's find the value of x.

(i) 40°

→ The value of x is 40°.

• Because in an isosceles triangle two angles and sides of the triangle are always the same.

(ii) 45°

• Sum of angles of the triangle = 180°. Let the unknown angle be x.

→ x + 45° + 45° = 180°

→ x + 90° = 180°

→ x = 180°- 90°

→ x = 90°

∴ x = 90°

(iv) 100°

• Sum of angles of the triangle = 180°. Let the unknown angle be x.

→ x + x + 100° = 180°

→ 2x + 100° = 180°

→ 2x = 180° - 100°

→ 2x = 80°

→ x = 80/2

→ x = 40°

∴ x = 40°

(v)

• Here, one angle is 90° because it is a right-angle triangle.

→ x + x + 90° = 180°

→ 2x + 90° = 180°

→ 2x = 180° - 90°

→ 2x = 90°

→ x = 90/2

→ x = 45°

∴ x = 45°

(vii) 120°

→ x + 120° = 180°

→ x = 180° - 120°

→ x = 60°

∴ x = 60°

(viii) 110°

• The exterior angle is equal to the sum of opposite internal angles.

→ x + x = 110°

→ 2x = 110°

→ x = 110/2

→ x = 55°

∴ x = 55°