Dynamic Geometry: Langley's Problem,
Isosceles Triangle, 20, 50, 60, 80 Degrees, Angle. HTML5 Animation for Mobile Devices. Click the Next button
below to start the stepbystep solution.
In an isosceles triangle ABC (AB = BC), E is on AB and D is on BC.
If angle B = 20 degrees, angle DAC = 60 degrees, and angle ACE =
50 degrees, find the measure of angle ADE. Click the next
(play) button
below to start.
