Multiple Choice Question (MCQ)
In the figure, if congruent right triangles ABD and DCA share leg AD , then \alpha =

×
90

×
100

×
110

✓
120

×
130
In the figure, if congruent right triangles ABD and DCA share leg AD , then \alpha =
90
100
110
120
130
Since one of the internal angles in the right triangle is 60\degree, the other one is 30\degree.which yields equilateral triangles as highlighted. \alpha is the double of 60\degree
D is the choice