MathDB

ABC=90^o, BCD=30^o, AB = CD, BC = 2AD, prove BAD=30^o

Source: IGO 2015 Elementary 3

July 22, 2018

geometryElementaryangles

Problem Statement

In the figure below, we know that

AB = CD

and

BC = 2AD

. Prove that

\angle BAD = 30^o

. https://3.bp.blogspot.com/-IXi_8jSwzlU/W1R5IydV5uI/AAAAAAAAIzo/2sREnDEnLH8R9zmAZLCkVCGeMaeITX9YwCK4BGAYYCw/s400/IGO%2B2015.el3.png