Internal and External Bisectors of an Angle

Internal and external bisectors are geometric tools that can be used to divide an angle into two equal parts. An angle is formed by two rays that have a common endpoint. The point of intersection of the rays is called the vertex of the angle. The two rays are called the sides of the angle. The angle is measured in degrees or radians.

Internal Bisector

An internal bisector of an angle is a line segment that bisects the angle into two equal parts. The internal bisector passes through the vertex of the angle and divides the angle into two smaller angles. The two smaller angles are congruent, which means that they have the same measure.

External Bisector

An external bisector of an angle is a line segment that bisects the angle into two equal parts. The external bisector does not pass through the vertex of the angle. Instead, it is located outside the angle. The external bisector also divides the angle into two smaller angles. The two smaller angles are congruent.

Acute, Straight, Right, and Reflex Angles

An acute angle is an angle that measures less than 90 degrees. A straight angle is an angle that measures exactly 180 degrees. A right angle is an angle that measures exactly 90 degrees. A reflex angle is an angle that measures greater than 180 degrees but less than 360 degrees.

The internal and external bisectors of an acute angle form two smaller acute angles. The internal and external bisectors of a straight angle form two right angles. The internal and external bisectors of a right angle form two smaller right angles. The internal and external bisectors of a reflex angle form two smaller reflex angles. Therefore, the correct answer is option 'C', which is "Right angle".