

Online Geometry Problem 712: Semicircle, Diameter, Tangent,
Perpendicular, Angle Measure.
Level: High School, Honors Geometry, College,
Mathematics Education

The figure shows the semicircles O and O' tangent at
B. AB is the diameter of semicircle O, AC is tangent to semicircle O' at
D, and DF is perpendicular to AB. If the measure of angle CAB is 25
degrees, find the measure of angle CFB.







