The following problems are easy to solve. All you need to do is think of it a little bit.

1. From the figure below, ABCD is a square and AED is an equilateral triangle. Find the angle BCE labeled to as θ.
   

2. Find the radius of the circle shown below.
   

3. Find the radius of the circle tangent to the three semi-circles as shown if the two smaller semi-circles are 10 units in radius.
   

Drawing Tip:
Download the pictures above and save it to your hard disk. Open it with any photo editing software (MS Paint will do). Edit the drawing to depict your analysis then upload your edited drawing to show it in your comment.