EXERCISE 18

1.The three angles of a quadrilaterals are 110 deg , 71 deg and 70 deg. Find its fourth angle.

2.In a quadrilateral PQRS, angleP=120 deg and angleQ=angleR=angleS, find angleQ , angleR and anglesS

3.In the adjoining figure, P is a point in the interior of angleAOB and angleAOB=40 deg. If Pmperpendicular

4.Find the unknown angles

(i)

(ii)

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

6.ABCD is a quadrilateral. AO and BO are the angl bisectors of angles A and B which meet at O. If angleC=70 deg and angleD=50 deg, find angleAOB .