<u>Part 1) which angle is congruent to Angle 1?</u>
we know that
When two lines are crossed by another line (which is called the Transversal), the angles in matching corners are called <u>corresponding angles</u>
m∠5=m∠1 ----------> by corresponding angles postulate
therefore
<u>the answer Part 1) is </u>
Angle
Part 2) Which can be used to directly prove that Angle 1 =~ Angle 8?
we know that
<u>Alternate exterior angles</u> are defined as two exterior angles on opposite sides of a transversal which lie on different parallel lines.
in this problem
m∠1=m∠8 -------> by alternate exterior angles theorem
therefore
<u>the answer part 2) is the option </u>
Alternate Exterior Angles Theorem
<u>Part 3) If m Angle 5 = 42 degrees, what is m Angle 4?</u>
we know that
<u> Alternate interior angles</u> are two interior angles which lie on different parallel lines and on opposite sides of a transversal
m∠4=m∠5 --------> by alternate interior angles theorem
so
m∠4=
therefore
<u>the answer Part 3) is</u>