# math (geometry)

posted by .

It says:
Find the area of a rectangle with length 12 inscribed in a circle with radius 7.5.

I know when they're talking about a radius with a figure, they're talking about the length between the center of the circle to a corner of the figure. But that usually works only with a regular figure, and a rectangle isn't one.

Does anyone have any ideas on how to solve it?

• math (geometry) -

Since the radius is 7.5, then the diameter is 15. Doesn't that make your rectangle 12 by 15?

• math (geometry) -

Oh wait! I see where you're getting at. I think since the diameter of the circle is 15, it will make a diagonal within the rectangle to make a right triangle. Therefore, the dimensions of the rectangle are 12 by 9.

Thanks soooooo much, Ms. Sue! You helped me a lot. (the diameter thing got me going! lol)

• math (geometry) -

You're very welcome. :-)

• math (geometry) -

since the radius is 7.5 the diameter will be 15 units.
from the pythagoras theorem Dsqaure=12Square + XSquare, where x= the unknown quantity.
Therfore; x= Root of((15x15) - (12x12)) = 9
Thank you!