I have this question, but I do not understand the wording of it.

For part a, I have used pythagoras to find y

$\displaystyle (4y)^2=180^2+50^2$

$\displaystyle (4y)^2=34900$

$\displaystyle 4y=186.8$

$\displaystyle y=46.7cm$

Therefore $\displaystyle y$ = 467mm

Can someone help me with part b?

Nevermind, I worked it out by picturing the bigger right-angled triangles.