501 Geometry Questions

Vertical Angles

When two straight lines intersect, the nonadjacent pairs of angles formed
(the angles that are opposite from each other), are called vertical angles.
Vertical angles are always congruent and have equal angle measures.

∠POT and ∠QOS are straight angles

∠POQ ∠SOT m∠POQ = m∠SOT

∠POQ and ∠SOT are vertical angles

∠POS ∠QOT m∠POS = m∠QOT

∠POS and ∠QOT are vertical angles

Other Angles That Measure 180°

When three line segments intersect at three unique points to make a closed
figure, they form a triangle. The interior angles of the triangle are the
angles inside the closed figure. The sum of a triangle’s three interior angles
is always 180°.

t

c a

mc + ma + mt = 180°

PQ

ST

O

501 Geometry Questions