Question

How are perpendicular and intersecting lines alike? How are they different?

Answer 1

Perpendicular lines meet each other  always at an angle of 90 while intersecting lines may or may not have an angle of 90.
Their opposite angles(made by intersecting lines) are  always same. 
And even, we can say every perpendicular lines as intersecting but can't say that every intersecting line is perpendicular.

Answer 2

Possible answers: both types of lines cross at a point. Intersecting lines form 4 angles. Perpendicular lines are intersecting lines which form only right angles.