posted by HELP ME...uRGENT! on .
ABCD is a quadrilateral with ∠ADC=∠ACD, ∠ACB=∠ABC and CD=7. If triangles ADC and ABC have perimeter 51 and 59, respectively, what is the value of BC?
∆ACD and ∆ACB are isosceles
So, AD=AC and AB=AC
AC = (51-7)/2 = 22
So, BC=59-22-22 = 15