Question

Geometry: Write a formal proof, ASAP!!!

Answer 1

${\qquad\qquad\huge\underline{{\sf Answer}}}$

Here we go ~

As we can see in the figure, lines m and n are parallel to each other. so we can apply Angle pair properties ~

So,

$\qquad \sf  \dashrightarrow \: \angle1 \cong \angle2$

[ they form corresponding angle pair ]

and it's given that :

$\qquad \sf  \dashrightarrow \: \angle2 \cong\angle 3$

therefore, by using above information. we can conclude that :

$\qquad \sf  \dashrightarrow \: \angle1 \cong \angle3$