Perpendicular Transversal Theorem

In a plane, if a line is perpendicular to one of two parallel lines, then it is perpendicular to the other line also.

 

Given:

Prove:

Proof

Statement
Reason
1
Given
2
is a right angle
Definition of perpendicular  lines
3
Definition of right angle
4
Corresponding angles
5
Definition of congruent angles
6
Substitution Property
7
is a right angle
Definition of right angle
8
Definition of perpendicular lines