1. Lesson 2 Geometry
Review

2. TYPES OF LINES 1. Parallel Lines - Two lines that never intersect.
2. Perpendicular lines
- Two lines that intersect forming right angles.

3. Types of Angles Right angle - an angle with 90 degrees
- an angle between 0 – 90 degrees
Acute angle
Obtuse angle
- an angle between 90 – 180 degrees
Straight angle
- an angle with 180 degrees in it.

4. Polygons
Polygons are simple, closed, planar geometric figures whose sides are line segments.
The number of sides is the same as the numbers of angles.
Concave polygons have an indentation
Convex polygon has no indentations.

5. Types of Polygons Triangles Quadrilateral Pentagon Hexagon Heptagon
Octagon
Nonagon
Decagon
Undecagon
Dodecagon
N- gon
Has three sides
Has four sides
Has five sides
Has six sides
Has seven sides
Has eight sides
Has nine sides
Has ten sides
Has eleven sides
Has twelve sides
Has N- sides

6. Types of Quadrilaterals
Has one set of parallel sides.
Has two sets of parallel sides
A parallelogram with all equal sides
A parallelogram with all right angles
A Rectangle with all equal sides.
Trapezoid
Parallelogram
Rhombus
Rectangle
Square

7. Regular Polygons
A regular polygon has all equal sides and all equal angles.
A square is an example of a regular quadrilateral.
Here are some other examples.

8. TRIANGLES In regards to the angles Right has 1 right angle Obtuse
Has 1 obtuse angle
Acute
Has all acute angles
Equiangular
All angles are equal.
In regards to the sides.
Equilateral
All sides are equal
Isosceles
2 equal sides
Scalene
No equal sides.

9. Triangles How many degrees are in the sum of the angles of a triangle?
If you have a regular triangle how many degrees are in each of the three angles?
180/3 =
60 degrees.