Question: Classify Each One of the Following Angles as Right, Straight, Acute, Obtuse or Reflex

a) 45 degrees      b) 90 degrees     c) 135 degrees      d) 180 degrees

An angle is formed when two lines meet at a point.

Answer:(a) 45 degrees- Acute angle ; (b) 90 degrees  - Right Angle     (c) 135 degrees - Obtuse Angle     (d) 180 degrees- Straight Angle

Explanation:

An angle is formed when two rays meet at a point.

An acute angle is less than the right angle.

The obtuse angle is greater than the right angle but smaller than the straight angle.

A reflex angle is greater than a straight angle.

a) Since 45 degrees is less than the right angle, it is an acute angle.

b) 90 degrees is called a right angle.

c) 135 degrees is greater than 90 degrees and an angle that is greater than the right angle (90 degrees) and less than 180 degrees is an obtuse angle.

d) 180 degrees is called a straight angle.

Thus, (a) 45 degrees Acute angle ; (b) 90 degrees  - Right Angle     (c) 135 degrees - Obtuse Angle     (d) 180 degrees- Straight Angle