Problem: In triangle ABC,CA=CB. On CB square BCDE is constructed away from the triangle. If x is the number of degrees in angle DAB, then
Answer Choices:
A. x depends upon triangle ABC
B. x is independent of the triangle
C. x may equal angle CAD
D. x can never equal angle CAB
E. x is greater than 45β but less than 90β
Solution:
β ACB=180ββ2A. Since CA=CD,
β CAD=21β[180ββ(β ACB+90β)]
=21β[180ββ(180ββ2A+90β)]
=Aβ45β
=AβX.
\therefore X=45^