#### Classification of Triangles by Their Sides:

**Isosceles Triangle**: They has two sides that are the exact same length but do not have to be the same degrees.

**Equilateral Triangle**: All the lengths and angles are the exact same

**Scalene Triangle**: No sides are the same length. No angles are the same degrees

#### Classifying Triangles by their Angles:

**Acute Triangle**: All of there angles are less than 90 degrees but they still add up to 180 degrees.

**Obtuse Triangle**: One of the angles is over 90 degrees, and the other two have to be less than 90 degrees.

**Right Triangle**: It has one 90 degree angle and then two other angles that add up to 90 they don't have to be equal. The side lengths do not matter.

#### Measuring Angles:

You can measure angles with a tool called a protractor. A protractor will tell you how many degrees and angle is. You can also use it to make your own angles.

#### Congruency:

When two triangles are completely equal with the lengths of the sides are the same and the degrees of the angles are the same.

There are four different ways to find out if they are congruent. Side side side, side angle side, angle side angle, angle angle side.

#### Orthocenter:

The point where three altitudes of a triangle meet.

#### Circumcenter

The point where the perpendicular bisectors of a triangle intersect. The circumcenter of the center of the triangles circumcircle.

#### Incenter

The center of the incircle of a triangle.