Question

In a quadrilaterals ABCD , if angleA=100 degree, angleB=60 degree, angleC=60 degree, then find angleD

Answer 1

angle D will be 100 because of the property that the opposite angles of parallelogram are always equal

Answer 2

We know that the sum of all angles of a quad. is 360 degree

Let angle D be x degree

then ,

100 + 60 + 60 + x = 360 ^0

or 220 + x = 360

or x = 360 - 220

therefore x = 40 degree