This is the concept of geometry, given that AB=AC, it means that the tirangle is isosceles, thus to get the value of AB and AC we proceed as follows; thus using the cosine rule: c^2=a^2+b^2-2abcosC suppose\AB=AC=x thus; 8^2=x^2+x^2-2*x*xcos15 64=2x^2-2x^2cos15
