Answer:
Answer One - Angles forming a linear pair sum to 180
Answer Two - Substitution
Answer Three - Definition of perpendicular lines
Step-by-step explanation:
<SWT and <TWU are supplementary because together they make a straight line, which is a 180-degree angle. When supplementary angles are added together they equal 180. Therefore the reason is "angles forming a linear pair sum to 180"
Then, <TWU is replaced with <SWT. Since they are equal they can be substituted for each other.
The definition of a perpendicular angle is when two lines which meet at a right angle, which is 90 degree. Therefore, TV and SU are perpendicular.
