Question

What is the value of m in the figure below? If necessary, round your answer to

Answer 1

First

$\\ \sf\longmapsto BD^2=AD\times DC$

$\\ \sf\longmapsto BD^2=18^2+7^2$

$\\ \sf\longmapsto BD^2=324+49$

$\\ \sf\longmapsto BD^2=363$

$\\ \sf\longmapsto BD=\sqrt{363}$

$\\ \sf\longmapsto BD=19.2$

Now

Using Pythagorean theorem

$\\ \sf\longmapsto BD^2+CD^2=m^2$

$\\ \sf\longmapsto m^2=7^2+19.2^2$

$\\ \sf\longmapsto m^2=49+363$

$\\ \sf\longmapsto m^2=412$

$\\ \sf\longmapsto m=\sqrt{412}$

$\\ \sf\longmapsto m=20.3$

Nearest value in options is 18

Hence option a is correct