You have typed in the following equation:

When clicking on 'Solve' you are given an option to solve for 'A', 'r', 'h' or 'b'.

There is no solutions, because the solver is set to solve for 'A'.

For example, if you select solve for 'r' you will get the following solution:

Click here to see the step by step solution

You can obtain an explanation for any step by clicking on it. Please note that you cannot click on the very first expression, which is the original problem.