If the walls in your house were not perpendicular they would probably topple over and you would no longer have a daily life for perpendicular lines to affect.
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stand up... that is a perpendicular line right there. you are 90 degrees with respect to the floor.
Railway lines with sleepers? Lines of latitude crossed by a line of longitude?
Real life example of parallel lines are railroad tracks and rows in a garden. Also the lines on a basketball court are parallel
The walls of most buildings are perpendicular to the ground they are built on.
Just one example: If you want to build something like a cabinet, you would want the sides to be perpendicular to each other, and to the top and bottom. Otherwise the door may not open and close correctly.