If an angle is less than 90° it is an acute angle.
If an angle is between 90° and 180° it is an obtuse angle.
If an angle is greater than 180° it is a reflex angle.
There are 360° in a full revolution. Angles at a point add up to 360°.
Angles on a straight line add up to 180° and are called supplementary angles.
Angles in a triangle add up to 180°
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Corresponding angles are equal. |
Alternate angles are equal. |
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Interior angles add up to 180°. |
Vertically opposite angles are equal. |