I just started an introduction to geometry course on edx.org and there's an (unexpected) Algebra question to figure out an angle, but I don't really know anything about algebra and how to figure it out. I'm sure it's an easy Algebra problem, but I have no background.

Could someone please show me how to do the work for this question to arrive at the correct answer?

Thank you.

Edit:

The above image is small, here's a thumbnail to the full size image, hosted with postimages.

Could someone please show me how to do the work for this question to arrive at the correct answer?

Thank you.

Edit:

The above image is small, here's a thumbnail to the full size image, hosted with postimages.

Last edited: