Points a and b are the endpoints of an arc of a circle. chords are drawn from the two endpoints to a third point, c, on the circle. given m arch  ab=64° and ⦣abc=73°, m ⦣abc=__ ° and m arch  ac=__ °.

Angle ABC is an inscribed angle with AC as its arch while angle ACB is an inscribed angle with AB as its arch.

m ⦣ABC = 73° (Given)
m ⦣ACB = 32° (Since ACB is an inscribed angle, we will get the one half of the given arch AB 64° : 1/2 * 64 = 32°)
m arch AC = 146° (To compute for the arch, multiply angle ABC of 73° by 2 since angle ABC is an inscribed angle : 2 * 73 = 146)