Mathematics

Problem

Lines

m

and

n

are parallel and are cut by a transversal

t

. Angles

\angle 1

and

\angle 2

lie between

m

and

n

on the same side of

t

. Which of the following is always true? a)

\angle 1 = 90^{\circ}

\angle 1+\angle 2 = 180^{\circ}

\angle 1+\angle 2 = 90^{\circ}

\angle 1 = \angle 2