Answer :
"Adjacent" means next to each other. "Perpendicular" means at an angle of 90 degrees.
Rectangles (this includes squares) have adjacent perpendicular sides. So do right triangles.
Rectangles (this includes squares) have adjacent perpendicular sides. So do right triangles.
adjecent basically means "next to" and perpindicular is meeting at an right angle (90 degrees) so squares have them and right angle triangles do to.