In the diagram, point E lies on line segment AB, and triangles AED and BEC are isosceles. Also, angle DEC is twice ADE. What is the measure of EBC in degrees?
Both triangles are isosceles
Angle AED = 80°
Angle ADE = 180 - 2(80) = 20°
Angle DEC = 2ADE = 2 * 20 = 40°
Angle BEC = 180 - 80 - 40 = 60°
Angle EBC = (180 - 60) / 2 = 120 / 2 = 60°
