Warnock - Chapter 5

Classify triangles: Acute angle

all angles less than 90 degrees

Classify triangles: Right angle

one angle is 90 degrees

Classify triangles: Obtuse angle

one angle is more than 90 degrees

Classify triangles: Equiangular

all angles are congruent

Classify triangles: Scalene

no sides are congruent

Classify triangles: Isosceles

at least 2 sides are congruent

Classify triangles: Equilateral

all sides are congruent

Interior angles

angles that are inside of the triangle

Exterior angles

angles that are outside the triangle that form a linear pair with an interior angle

Triangle sum theorem

The interior angles add up to 180 degrees

The exterior angles theorem

an exterior angle of a triangle is equal to the sum of its remote (non-adjustent) interior angles

Congruent Polygons:

1. corresponding angles are congruent

2. corresponding sides are congruent

3. congruent statements MUST match up to corresponding parts

Third angle theorem

if 2 angles of 1 triangle are congruent to 2 angles of a second triangle, then their 3rd angles must be congruent

SSS

if the 3 sides of 1 triangle are congruent to the 3 sides of another triangle, then the triangles are congruent

SAS

if 2 sides and their included angle are congruent to 2 sides and the included angle in another triangle, then the triangles are congruent

ASA

if 2 angles and their included side are congruent to 2 angles and their included side in another triangle, then the triangles are congruent

AAS

if 2 angles and a non included side are congruent to 2 angles and the non included side opposite the same angle in another triangle, then the triangles are congruent

Way to tell that an angle or side is congruent

1. Using angle measures to find missing angles

2. Coordinates, distance formula, or given side measurements

3. Right angles or perpendicular segments

4. parallel lines → alternate interior, corresponding

5. vertical angles

6. vocabulary-bisec, impoint

7. if they share a side/angle - reflective property

HL congruence theorem

if the hypotenuse and a leg of one right triangle are congruent to the hypotenuse and leg of another right triangle, then the triangles must be congruent