Online Geometry Problem 832: Quadrilateral, Isosceles triangle, 70-70-40
degrees, Congruence, Auxiliary lines, Equilateral
triangle. Level: High School,
SAT Prep, College,
Mathematics Education

The figure below shows a quadrilateral ABCD
with AD = BC, angle BAD = angle ADB = 70 degrees, and angle BDC = 20
degrees. Find the measure of angle CBD. Problem submitted by Charles
T.