Question

A, B, C and D are points on the circumference of a circle, and the center is O. AC is the diameter of the circle. AC and BD intersect at E.

Answer 1

`m\angle DAC=35^(\circ)`

Explanation:

Arc
`BC=50^(\circ)` (inscribed angle theorem)

Arc
`AB=130^(\circ)` (semicircle)

`m\angle ADB=65^(\circ)` (inscribed angle theorem)

`m\angle DEA=80^(\circ)` (linear pair)

`m\angle DAC=35^(\circ)` (angle sum of a triangle)