How far is car from center of Ferris wheel?

Question

A Ferris wheel is elevated $1\text{ m}$ above the ground. When a car reaches the highest point on the Ferris wheel, its altitude from the ground level is $31\text{ m}$. How far away from the center, horizontally, is the car when it is at the altitude of $25\text{ m}$?

I don't get it please where to start and how to solve it

Answer 1

Here is a picture.

You should be able to find $r$ and $a$ fairly easily use the Pythagorean theorem to find $b$

Answer 2

Using Doug's Diagram: If the altitude with the base is 31 then your diameter is 30, which helps you get $r$ your radius. $d=2r$

$30=2r$, $r=15$

To find $a$, given that the base is at 1,you need to move the center along the radius. So the center of the ferris wheel is $16$ $a= 25-16=9$

Pythagorean theorem: $a^2+b^2=r^2$

$9^2+b^2=15^2$

$81+b^2=225$

$b^2=225-81=144$

$\sqrt {b^2}=\sqrt {144}$

$b=12$