Question

HELP ME PLEASE??????

Answer 1

The measure of an angle formed by a two secants drawn from a point outside the circle is half the the difference of the intercepted arcs, so:

$\cfrac{85^o - arcBD}{2}=20^o \\ \\ 85^o-arcBD = 40^o \\ \\ arcBD = 85^o - 40^o = 45^o$