Angle is formed by two rays that have a common end point. There are some types of angle. Here they are.
Table of Contents
Type of Angle
In general, there are some kinds of angles:
1. Acute angle (less than 90°)
Learn more about acute angle.
2. Right angle (90°)
3. Obtuse angle (more than 90° but less than 180°)
Learn more about obtuse angle.
4. Straight angle (180°)
5. Reflect angle (more than 180°)
Learn more about reflect angle.
If two parallel lines are cut by another line (transversal) then there are angles that have same measure (same magnitude) which is called corresponding angles.
Corresponding Angels Theorem
Corresponding angles theorem says that
“If a transversal cuts two parallel lines, their corresponding angles are congruent”
Based on the theorem, there is eight angles that can be used to solve the angle’s problems
For more details, look at the picture.
Based on the picture, lines a parallel with line b and they are cut by line c so there are angles that have same measure (same magnitude) which is called corresponding angles.
Based on the theorem, there are:
1. Alternate interior angles
Pair of alternate interior angles has same measure. Based on the picture, alternate interior angles are ∠a4 = ∠b2, and ∠a4 = ∠b2.
2. Alternate exterior angles
Pair of alternate exterior angles has same measure. Based on the picture, alternate interior angles are ∠a1 = ∠b3, and ∠a2 = ∠b4.
3. Consecutive interior angles
Sum of the pair of consecutive interior angles is 180°. They are ∠a4 + ∠b1 = 180° and ∠a3 + ∠b2 = 180°.
4. Consecutive exterior angles
Sum of the pair of consecutive exterior angles is 180°. They are ∠a1 + ∠b4 = 180° and ∠a2 + ∠b3 = 180°.
5. Corresponding angles
Pair of corresponding angles has same measure. Based on the picture, they are ∠a1 = ∠b1, ∠a2 = ∠b2, ∠a3 = ∠b3, and ∠a4 = ∠b4.
6. Vertical angles
Pair of vertical angles has same measure. Based on the picture, they are ∠a1 = ∠a3, ∠a2 = ∠a4, ∠b1 = ∠b3, and ∠b2 = ∠b4. It is also called ∠a1 is opposite of ∠a3.
Corresponding Angles Examples
- Find the a, b, and c!
2. Find the x!