Suppose that m∠a = m∠d. which other fact would guarantee that the triangles are similar? a) ab de = cb fe b) m∠c = m∠f c) m∠a + m∠b + m∠c = 180° d) 180° - m∠d = m∠e + m∠f

Given that m∠A=m∠D. The facts that would guarantee similarity of triangle ABC and triangle FDE is :
The ratio of corresponding sides are similar, that it:
AB/DE=CB/FE=CA/FD
also the corresponding angles should be equal. 
hence the answer is:
A] AB/DE=CB/FE and m∠C=m∠F

Polar coordinates is 8,9