Lesson 2 Geometry

1
Lesson 2Geometry

• 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.
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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.

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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

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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

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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.

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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.

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Triangles

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