1. Draw a coordinate plane.

2. Use the origin as vertex C of the triangle CDE.

3. Place the base of the triangle along the positive x- axis.

4. Position the triangle in the first quadrant.

5. Since D is on the x-axis, its y-coordinate is 0.

     Its x-coordinate is a because each side has length a units.

6. Triangle CDE is an equilateral triangle, so the x-coordinate of E is halfway between 0 and

    a that is .

7.Since is an equilateral triangle, y-coordinate of E is  a units.