Re: 2012 Year 9 &10 Mathematics Marathon
ooo how about this?
Draw a perpendicular line from A to BC, naming the line x. Name the left equal side y, and right equal side z.
sin B = x/y
y=x/sin B
sin C= x/z
z=x/sin C
Given y=z,
x/sin B = x/sin C
Cancel x's, sin C = sin B, so C=B +k180 or...