Move Points A,B,C[br]Notice that c/c' = b/b' = a/a'

The ratio of the areas of two similar triangles equals the ratio of the squares of any pair of corresponding sides. Area ABC ÷ Area DEF = b^2 ÷ b'^2.[br]This is derived as follows: Area ABC ÷ Area DEF[br]= 0.5 * c * b ÷ 0.5 * c’ * b’ [br]= c * b ÷ c’ * b’ (but c ÷ c’ = b ÷ b’)[br]= b * b ÷ b’ * b’ => b^2 ÷ b’^2