Question

ABCD is a quadrilateral in which AB=CD and AD=BC find angleD,angleC and angleB​

Answer 1

from the above mentioned information...

a quadrilateral which have opposite sides same in length is parallelogram. so the above quadrilateral is parallelogram.

adjacent angles are supplementary..

d+a=180;d=180-a

opposite angles are equal in a quadrilateral.so..

d=180-a=b

similarly..b&c are adjacent angles....

b+c=180; c=180-b

Answer 2

Answer:

angle D = 90°

angle C = 90°

angle B = 90°