# Geometry Day 1+2

## 30 terms

### Degree

A measure for angles. There are 360 degrees in a full rotation

### Complementary Angles

Two angles that add up to 90 degrees (they don't have to be next to each other)

### Supplementary Angles

Two angles that add up to 180 degrees (they don't have to be together to be supplementary)

### Right Angle

An angle that is equal to 90 degrees

### Obtuse Angle

An angle that is more than 90 degrees but less than 180 degrees

### Acute Angle

An angle that is less than 90 degrees

### Straight Line

A straight angle measures 180 degrees (it looks like a straight line)

### Line

-Is straight (no curves)
-has no thickness,
- extends in both direction

### Line Segment

A line with definite end points

### Ray

A line with a start point but no endpoint (it goes on forever)

### Vertex

A point where two points meet. The plural of vertex is vertices

### Perpendicular

Perpendicular lines are lines that meet at right angles

### Parallel

Always the same distances apart and never touch. Will never meet.

### Polygon

A closed figure whose sides are all line segments

### Regular Polygon

A polygon in which all sides are congruent (equal measure) and all angles are congruent

### Triangle

A polygon that has three sides

### Acute Triangle

A triangle in which all angles are less than 90 degrees

### Obtuse Triangle

A triangle in which one angle is greater than 90 degrees

### Right Triangle

A triangle in which one angle is equal to 90 degrees

### Scalene Triangle

A triangle in which all sides and angles are not congruent

### Isosceles Triangle

A triangle in which two sides and two angles are congruent

### Equilateral Triangle

A triangle in which two sides and angles are congruent

A four sided polygon

### Parallelogram

A four sided polygon in which opposite sides are congruent, opposite sides are parallel, and opposite angles are congruent

### Rectangle

-A four sided polygon that has all the properties of a parallelogram
-opposite sides are congruent and parallel
-opposite angles are congruent and equal to 90 degrees

### Rhombus

-A four sided polygon that has all the properties of a parallelogram

### Square

-A four sided polygon that has all the properties of a parallelogram,rectangle, and rhombus
-All sides and all angles are congruent

### Trapezoid

A four sided polygon with exactly 1 pair of parallel opposite sides

### Kite

A four sided polygon that has two pairs of adjacent congruent side and has congruent opposite angles

equal