Question

What is the perpendicular adjacent sides in the triangle

Answer 1

"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.

Answer 2

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.