ah=hc=bc=ab=cd

Triangle chd is an equilateral triangle.

Triangle adh is an isosceles triangle

Angle AHC= angle B= 100

Angle AHD= Angle AHC- Angle DHC= 100-60=40.

Angle DAH=( 180- angle AHD)/2=70.

Angle bar = angle BCH = 80°.

Angle difference = 10