Question

What is m angle H + m angle J?

Answer 1

180°

Explanation:

The measure of an inscribed angle (inscribed inside a circle) is half the measure of its inscribed arc.

m∡H = (1/2)(m arc GJI)

m∡J = (1/2)(m arc GHI)

m∡H + m∡J = (1/2)(m arc GJI + m arc GHI)

But those two arcs added together on the right side are the whole circle, so they add to 360°.

m∡H + m∡J = (1/2)360°

m∡H + m∡J = 180°