Page 60 - Concepts of Reasoning-8

Worksheet-12.3

Interior Angles of a Quadrilateral

1. Choose the correct answer for each of the following :
a. In the given figure, the value of x is:
I L
90° 80°
i. 100° ii. 90°
iii. 120° iv. 160°

90° X°
b. In the given figure, the value of x is: J K B C
120° 72°
i. 58° ii. 48°

iii. 68° iv. 38° x°
A 110°
c. In the given figure, the measurement of angle F is: F G D
(5X + 12)° 86°
i. 122° ii. 100°

iii. 112° iv. 102° 42°
E 120°
H
d. In the given figure, the unknown angles M and O are: P O
100° (15x – 7)°
i. 72° and 90° ii. 70° and 80°

iii. 70° and 90° iv. 70° and 83° (12x – 2)° 107°
I L M N
e. In the given figure, the unknown angles J, L and K are:
90° (20x – 10)°
i. 100°, 80° and 120° ii. 90°, 80° and 120°

iii. 90°, 80° and 110° iv. 90°, 70° and 110° (24x – 10)° (30x – 10)°

2. Solve the following word problems : J K

a. A regular polygon has 40 sides. Find the measures of the interior and exterior angles of the
polygon.

___________________________________________________________________________
___________________________________________________________________________

b. Find the number of sides of a regular polygon whose exterior angle has a measure of 40°.

c. In a hexagon, three angles are congruent to the other three angles. The three angles are 15x, 14x
and 7x. Find all the angles of the hexagon.
___________________________________________________________________________

___________________________________________________________________________

60 Reasoning - 8