Chapter 2

Question 1

Parallel Postulate

Answer 1

If two lines are cut by a transversal and the sum of the interior angles is less than 180 then, those two lines will intersect on that side of the transversal.

Question 2

Complementary angles

Answer 2

90

Question 3

Supplementary angles

Answer 3

180

Question 4

Vertical angles

Answer 4

Opposite angles on perpendicular lines

Question 5

Triangle Inequality Theorem

Answer 5

Decides whether it’s possible for 3 points to from a triangle. The sum of any two sides MUST be larger than the third side. If this criteria isn’t met then a triangle CANNOT be formed.

Question 6

Concurrence

Answer 6

when 3 or more lines meet at a single point

Question 7

Medians

Answer 7

Lines drawn from the vertices that bisect the opposite side.

Question 8

Centroid

Answer 8

Where median lines meet, AKA center of mass

Question 9

Altitudes

Answer 9

Perpendicular lines drawn from vertex to opposite side

Question 10

Orthocenter

Answer 10

Where altitude lines meet

Question 11

Angle bisector

Answer 11

Lines drawn from the angle that split the angle in half

Question 12

Incenter

Answer 12

Where angle bisectors meet.

Question 13

Perpendicular bisectors

Answer 13

evenly split 3 sides of the triangle

Question 14

circumcenter

Answer 14

where perpendicular bisectors meet

Question 15

Polygon

Answer 15

Any 2D shape with straight AND connecting lines, number of sides tells you the name

Question 16

Polygon shape chart
Triangle
square
rectangle
quadrilateral
pentagon
hexagon
heptagon
octagon
nonagon
decagon
n-gon

Answer 16

3
4
4
4
5
6
7
8
9
10
n

Question 17

Regular polygons

Answer 17

All sides have the same length and all angles have the same measure.

Question 18

Exterior angle

Answer 18

The measurement between the shape and each line segment when extended past the shape

Formula: 360/n

Question 19

Interior angle

Answer 19

The supplementary angle to the exterior angle

Formula: 180-(360/n) OR (n-2)x180/n

Question 20

Finding the Area of a regular polygon

Answer 20

1). Split into double the amount of triangles than sides
2). find the interior angle measure and split in half. this will be angle measure for all the triangles
3). use 180 rule to find the missing two angles
4). use tangent O/A to find all info needed for A=.5bh
5). Multiply that number by however many triangles you have and put it in units squared.