What is the value of m in the figure below? if necessary, round your answer to the nearest tenth of a unit

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

both equations and proportions are better.