Question

∠ABD is formed by a tangent and a secant intersecting outside of a circle. If minor arc AC = 78° and minor arc CD = 124°, what is the measure of ∠ABD?

Answer 1

I believe the measure of angle ABD is 79 degrees. You must add the measures of arc CD and AC first. 78+124=202 To figure out the measure of arc AD, subtract 202 from 360. 360-202=158 Because arc AD is a major arc, the angle that opens up to it, ABD, is half its measure. This means that angle ABD is 79 degrees. Hope this helped!