Q108 of 160 Page 144

The interior angles of the triangle are in the ratio 1:2:3, then the ratio of its exterior angles is 3:2:1.

False,

Given:

Ratio of interior angles = 1:2:3

Let the interior angles be x, 2x and 3x

Now, the sum of the interior angles of the triangle are 180⁰

⇒ x+ 2x + 3x = 180⁰

⇒ 6x = 180⁰

⇒ x =

⇒ x = 30⁰

Therefore, the interior angles are: 30⁰, 60⁰ and 90⁰.

Now, the exterior angles will be found by subtracting from 180⁰ because they form a linear pair.

The exterior angles are: 150⁰, 120⁰ and 90^0.

106

State whether the statements are true (T) or false (F).

If diagonals of a quadrilateral are equal, it must be a rectangle.

107

State whether the statements are true (T) or false (F).

If opposite angles of a quadrilateral are equal, it must be parallelogram.

109

State whether the statements are true (T) or false (F).

is a concave pentagon.

110

State whether the statements are true (T) or false (F).

Diagonals of a rhombus are equal and perpendicular to each other.