You can
put this solution on YOUR website! Two chords intersect in a circle forming right angles. What is the sum of the
measures of a pair of opposite arcs?
The measure of an angle formed by two intersecting chords is one-half
the sum of the measures of the arcs intercepted by it and its vertical
angles.
The sum of the measures of the two red arcs is therefore twice
the measure of the right angle indicated in red or 180° and the
sum of the measures of the two green arcs is twice the measure of
the right angle indicated in green, or 180°.
The answer is 180°. Were you asked to prove that, or just
answer it?
Edwin
