# Types of Angles

Acute Angle-an Angle Between 0 and 90 Degrees

acute angle An angle that measures less than 90 degrees. right angle An angle that measures exactly 90 degrees. obtuse angle An angle that measures betwwen 90 and 180 degrees. straight angle An angle that measures exactly 180 degrees. An angle that measures exactly 180 degrees. Angles whose measure adds up to 90 degrees.

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Acute Triangle

An acute triangle is a triangle with all three angles acute (less than 90°). An obtuse triangle is one with one obtuse angle (greater than 90°) and two acute angles. Since a triangle's angles must sum to 180°, no triangle can have more than one obtuse angle.

Equilateral Triangle

In geometry, an equilateral triangle is a triangle in which all three sides are equal. In the familiar Euclidean geometry, equilateral triangles are also equiangular; that is, all three internal angles are also congruent to each other and are each 60°.

Isosceles Triangle

There are three special names given to triangles that tell how many sides (or angles) are equal. There can be 3, ... Right Isosceles Triangle . Has a right ...

Obtuse Angle-an Angle Between 90 and 180 Degrees

Parts of an Angle. The corner point of an angle is called the vertex. And the two straight sides are called arms. The angle is the amount of turn between each arm.. How to Label Angles. There are two main ways to label angles:

Obtuse Triangle

Obtuse Triangle. more ... A triangle that has an angle greater than 90° See: Acute Triangle. Triangles - Equilateral, Isosceles and Scalene.

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Right Angle-an 90 Degree Angle

Right angle. In geometry and trigonometry, a right angle is an angle of exactly 90° (degrees), corresponding to a quarter turn. If a ray is placed so that its endpoint is on a line and the adjacent angles are equal, then they are right angles.

Scalene Triangle

Equilateral, Isosceles and Scalene. There are three special names given to triangles that tell how many sides (or angles) are equal. There can be 3, 2 or no equal sides/angles:

Straight Angle-a 180 Degree Angle

A straight angle is 180 degrees. This is a straight angle. A straight angle changes the direction to point the opposite way. Sometimes people say "You did a complete 180 on that!" ... meaning you completely changed your mind, idea or direction.