Given: Quadrilateral BCDF is a rhombus. Point A is on the extension of the line BC past B and is positioned so that AF is parallel to the diagonal BD and meets the extension of CD at E. Angle ACD measures 100 degrees.
To Find: The measure of angle CEA.
Solution
Angles angle B1 and angle D1 are equal to 40 degrees. Angle AEC equals angle B1 by the theorem on corresponding angles.
