S.chand Class 8 Maths Solution Chapter 12 Quadrilaterals Exercise 12

 Exercise 12

Question 1

1. The three angles of a quadrilateral are $65^{\circ}, 55^{\circ}$ and $130^{\circ}$. Find its fourth angle.

2. The two adjacent angles of a quadrilateral are $75^{\circ}$ and $125^{\circ}$. The other two angles are equal. Find the measure of each of these equal angles.

3. In a quadrilateral $A B C D, \angle A=150^{\circ}$ and $\angle B=\angle C=\angle D$, find $\angle B, \angle C$ and $\angle D$.

4. In the adjoining figure, $P$ is a point in the interior of $\angle A O B$ and $\angle A O B=40^{\circ}$. If $P M \perp O A$ and $P N \perp O B$, find the measure of $\angle M P N$.

5. A quadrilateral has all four angles of the same measure, what is the measure of each angle ?

6. Two angles of a quadrilateral measure $55^{\circ}$ each. The third angle is $140^{\circ}$. What is the measure of the fourth angle ?

7. Find the measures of the four angles of a quadrilateral if they are in the ratio $3: 5: 7: 9$.

8. $A B C D$ is a quadrilateral. $A O$ and $B O$ are the angle bisectors of angle $A$ and $B$ which meet at $O$. If $\angle C=70^{\circ}, \angle D=50^{\circ}$, find $\angle A O B$.

Multiple Choice Questions (MCQs)

9. The fourth angle of the quadrilateral that has three acute angles is

(a) acute

(b) right

(c) obtuse

(d) straight

10. The value of y in the given figure is :

(a) 89°

(b) 91°

(c) 101°

(d) 79°

11.What is the value of a ?

(a) 90°

(b) 10°

(c) 180°

(d) 2°

High Order Thinking Skills (HOTS)

12.Find the values of x, y and z in the diagram. Give reasons wherever necessary.

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