How are perpendicular lines similar to intersecting lines? how are they differrent ?

Perpendicular lines are connected, and form two 90º angles. Although they connect, they do not necessarily have to "cross over" each other. Intersecting lines, on the other hand, must cross over each other to form 4 angles. Note that the angles between intersecting lines do not have to be 90º.
Think of perpendicular lines like a Upper case T
Think of intersecting likes like an addition sign: +

Similarities: Both sets of lines create angles, and in both sets the two lines are connected in some way
Differences: Perpendicular lines ALWAYS form 90º angles, but intersecting lines don't have to. 

Hope this helps!