Answer:
D
Step-by-step explanation:
It turns out from similar triangles, that 7/BD = BD / 18. Use triangles ABD and BDC to show this relationship. Solving this equation will give you BD
BD^2 = 7*18
BD^2 = 126 Just leave it in this form. Do your rounding at the end.
Because triangle BDC is a right angle triangle, use the Pythagorean Theorem to solve for m
m^2 = BD^2 + 7^2
m^2 = 126 + 49
m^2 = 175 Take the square root of both sides.
sqrt(m^2) = sqrt(175)
m = 13.22
so the answer is D
