Question

A, B, C are any points on the circle with centre O. m(arc BC)=120${}^{\circ }$ and m(arc AB)=130${}^{\circ }.$
Then, find the value of m(arc ABC) .

Answer 1

By property of sum of measure of arcs, we must have
m(arc ABC) = m(arc AB) + m(arc BC)
$⟹$ m(arc ABC) = 130${}^{\circ }$ + 120${}^{\circ }$
= 250${}^{\circ }$