Determine which of the lines are perpendicular if any.explain

21.  ΔUYZ Obtuse

22. ΔBCD Right or Rectangle

23. ΔADB Acute

24. ΔUXZ Acute

25. ΔUWZ Right or Rectangle

26. ΔUXY Equiangular and acute

Step-by-step explanation:

We need to classify each triangle by its angles.

Acute: They have 3 acute angles (less than 90 degrees).

Rectangle: The inner angle A is straight (90 degrees) and the other 2 angles are sharp. The sides that form the right angle are called legs (c and b), the other side hypotenuse.

Obtuse: The inner angle A is obtuse (more than 90 degrees). The other 2 angles are acute.

ΔUYZ Obtuse  The inner angle Y is obtuse (more than 90°).

ΔBCD Right or Rectangle The inner angle C is straight (90°).

ΔADB Acute It has 3 acute angles (less than 90°).

ΔUXZ Acute  It has 3 acute angles (less than 90°).

ΔUWZ Right or Rectangle The inner angle W is straight (90°).

ΔUXY Equiangular and acute Which means all the inner angles are equal (60°).