Question

In the diagram below of ΔACD, B is a point on AC⎯⎯⎯⎯⎯such that ΔADB is an equilateral triangle, and ΔDBC is an isosceles triangle with DB⎯⎯⎯⎯⎯≅BC⎯⎯⎯⎯⎯.

Find m∠C. Explain your work/thought process.

Answer 1

equilateral triangle all angles add up to 180 and are equal so each angle is 60 degrees

angles on a line add up to 180.

angle CBD = 180-60 = 120

DBC is an isosceles triangle so it's base angles are the same.

180-120= 60

60/2=30