If two lines intersect at right angles then two lines are perpendicular

All definitions can be read as a conditional statement. They can be read forward (conditional) and backward (its converse). ex) perpendicular lines conditional If two lines are perpendicular, then they intersect to form right angles. converse If two lines intersect to form right angles, then they are perpendicular.

Hypothesis : If two lines intersect at right angles

Conclusion: The two lines are perpendicular