Question

In a quadrilateral ABCD, B=45,D=3 angle B, and C=2 angle B. Find the value of A

Answer 1

D=135. C=90
So B+D=45+135=180°
Similarly C+A=180
So A=90°

Answer 2

In quad. ABCD,
B=45
D=3×45=135
C=2×45=90
IN A QUAD OPP SIDES ARE SUPPLEMENTARY
therefore C +A=180
A=180-90
A=90