Unit 3

Front 1

Acute Triangle

Back 1

A triangle in which all measures are less than 90°

Front 2

Obtuse Triangle

Back 2

A triangle in which 1 angle measure is more than 90°

Front 3

Right Triangle

Back 3

A triangle in which 1 measure is equal to 90°

Front 4

Equiangular Triangle

Back 4

A triangle in which all measures are equal to 60° and are all congruent

Front 5

Scalene Triangle

Back 5

A triangle that has no congruent sides

Front 6

Isosceles Triangle

Back 6

A triangle with 2 congruent sides.

Front 7

Equilateral Triangle

Back 7

A triangle with all congruent sides

Front 8

Distance Formula

Back 8

d=✅(x#1-x#2)^2+(y#1-y#2)^2

Front 9

Corresponding Angle Postulate

Back 9

If two triangles are cut by a transversal then, each pair of congruent angles are congruent.

Front 10

Alternate Interior Angle Theorem

Back 10

If two triangles are cut by a transversal then, each pair of alternate interior angles are congruent.

Front 11

Consecutive Interior Angle Theorem

Back 11

If two triangles are cut by a transversal then, each pair of consecutive interior angles are supplementary.

Front 12

Alternate Exterior Angle Theorem

Back 12

If two triangles are cut by a transversal then, each pair of alternate interior angles is congruent.

Front 13

Angle Sum Theorem

Back 13

The sum of the angle measure of a triangle is always 180°.

Front 14

Third Angle Theorem

Back 14

If 2 angles of 1 triangle are congruent to 2 angles of a second triangle, then the third triangles are congruent.

Front 15

Exterior Angle Theorem

Back 15

The measure of an exterior angle of a triangle is equal to the sum of the measures of the remote interior angles.

Front 16

The acute triangles of a _____ _____ are complementary.

Back 16

Right triangle

Front 17

There can be at most 1 _____ or _____ angle in a triangle.

Back 17

Right or obtuse

Front 18

Definition of Triangle Congruence
(CPCTC)

Back 18

Triangles are congruent only if there corresponding parts are congruent.

Front 19

Reflexive Property of Triangle Congruence

Back 19

🔺jkl = 🔺jkl

Front 20

Symmetric Property of Triangle Congruence

Back 20

If 🔺jkl = 🔺abc, then 🔺abc = 🔺jkl

Front 21

Transitive Property of Triangle Congruence

Back 21

If 🔺jkl = 🔺abc, and 🔺abc = 🔺xyz, then 🔺jkl = 🔺xyz

Front 22

Congruence Transformation

Back 22

When a shape is transformed without changing size or shape.

Front 23

Side-Side-Side Congruence Postulate
(SSS)

Back 23

If all 3 sides of a triangle are congruent to all 3 sides of another triangle, the triangles are congruent.

Front 24

Side-Angle-Side Congruence Postulate
(SAS)

Back 24

If 2 sides and the included angle of one triangle are congruent to 2 angles and the included angle of another triangle, then the triangles are congruent.

Front 25

Angle-Side-Angle Congruence Postulate
(ASA)

Back 25

If 2 angles and the included side of one triangle is congruent to 2 angles and the includes side of another triangle, then the triangles are congruent.

Front 26

Angle-Angle-Side Congruence Theorem
(AAS)

Back 26

If 2 angles and a non included side of one triangle are congruent to 2 angles and a non included side of another triangle, then those 2 angles are congruent.

Front 27

Isosceles Triangle Theorum

Back 27

If 2 sides in a triangle are congruent, then the angles opposite those sides are congruent.

Front 28

Converse of Isosceles Triangle Theorem

Back 28

If two angles in a triangle ate congruent, then the two sides opposite the angles are also congruent

Front 29

A triangle is equilateral only if it's ...

Back 29

equiangular

Front 30

Each angle measure of a equilateral triangle measures...

Back 30

60°

Front 31

Triangle

Back 31

Polygon with 3 sides

Front 32

Quadrilateral

Back 32

Polygon with 4 sides

Front 33

Pentagon

Back 33

Polygon with 5 sides

Front 34

Hexagon

Back 34

Polygon with 6 sides

Front 35

Heptagon

Back 35

Polygon with 7 sides

Front 36

Octagon

Back 36

Polygon with 8 sides

Front 37

Nonagon

Back 37

Polygon with 9 sides

Front 38

Decagon

Back 38

Polygon with 10 sides

Front 39

Dodecagon

Back 39

Polygon with 12 sides

Front 40

Regular Polygon

Back 40

●All congruent sides and angles.
●Convex

Front 41

Area of a Circle

Back 41

pi(r)^2

Front 42

Perimeter of a Circle

Back 42

2pi(r)

Front 43

Any point on a perpendicular segment bisector is equidistant from the _____ __ __ _____

Back 43

endpoints of the segment

Front 44

Any point equidistant from both endpoints of a segment lies on the _____ _____ of the segment

Back 44

perpendicular bisector

Front 45

Concurrent Lines

Back 45

When 3 or more lines intersect

Front 46

Point of Concurrency

Back 46

Where concurrent lines meet

Front 47

Circumcenter

Back 47

The point of concurrency for the perpendicular bisectors of a triangle

Front 48

Circumcenter Theorem

Back 48

The circumcenter of a triangle is equidistant from the vertices of the triangle.

Front 49

Any point on the angle bisector is _____ from the sides of the angle

Back 49

equidistant

Front 50

Incenter Theorum

Back 50

The incenter of a triangle is equidistant from each side of the triangle.

Front 51

Incenter

Back 51

The point of concurrency for angle bisectors

Front 52

Centroid

Back 52

The point of concurrency for medians

Front 53

Centroid Theorum

Back 53

The centroid of a triangle is located two thirds of the distance from a vertex to a midpoint on a median

Front 54

Steps to find a Centroid using given points

Back 54

Step 1: Plot points
Step 2: Find midpoints
Step 3: Find Slope
Step 4: Find Equations
Step 5: Find Point of intersection by substituting

Front 55

Definition of Inequality

Back 55

For any real numbers a and b, a > b only if there is a positive number c such that a = b + c.

Front 56

Comparison Property of Inequality

Back 56

a < b, a = b, or a > b

Front 57

Transitive Property of Inequality

Back 57

If a < b and b < c, then a < c.
If a > b and b > c, then a >c.

Front 58

Addition and Subtraction Property of Inequality

Back 58

If a > b, then a + c > b + c and a - c > b - c

Front 59

Multiplication And Division Property of Equality

Back 59

a < b, then ac < bc and a/c < b/c

Front 60

Exterior Angle Inequality Theorem

Back 60

If an angle is an exterior angle of a triangle, then it's measure is greater than each of its corresponding remote interior angles.

Front 61

If one side of a triangle is longer than another side, then the longer side has a _____ _____than the a nice opposite the shorter side.

Back 61

greater measure

Front 62

If one angle of a triangle has a greater measure than another angle, then the side opposite the greater angle is _____ than the side opposite the lesser angle.

Back 62

longer

Front 63

Triangle Inequality Theorem

Back 63

The sum of the lengths of any two sides of a triangle is greater than the length of the third side.