This is a math help forum and not a home service site. On this forum we expect the student to be involved in finding the solution while the helpers here give leading hints. In order to give hints we need to see the work you have done so far, even if you know it is wrong. Then we have an idea of what type of help to offer. So please post back sharing your work with us!
Also, can you please post the exact problem? A picture would be best.