GEOMETRY REVIEW

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GEOMETRY REVIEW

• Grades 5 - 8

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• Point a location in space .
• Line-- a straight path that goes on forever in
  both directions.
• Line segment a straight path between 2 points,
  called its endpoints.
• A
  B

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• Ray a straight path that goes on forever in one
  direction from an endpoint.
• Angle two rays of line segments with a common
  endpoint, called the vertex.

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Types of lines

• Parallel lineslines that never meet and are the
  same distance apart.
• Intersecting lines lines that meet.

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Types of Angles

• Acute angle measures between 0 and 90 degrees.
• Obtuse angle measures between 90 and 180 degrees.

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Types of Angles

• Right angle measures 90 degrees.
• Straight angle measures 180 degrees.

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POLYGONS

• A polygon is a flat 2-dimensional figure made up
  of 3 or more line segments called sides.
• The sides of a polygon are connected end-to-end
  and make a closed figure.
• Each endpoint where two sides meet is called a
  vertex. The plural of vertex is vertices.

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REGULAR POLYGONS

• A regular polygon is a polygon whose sides all
  have the same length and whose angles are all the
  same size.
• We say that a regular polygon is both equilateral
  and equiangular.

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NAMES OF POLYGONS

• Polygons are named according to the number of
  sides.
• 3 sides--triangle 8 sides--octagon
• 4 sides--quadrilateral 9 sides--nonagon
• 5 sides--pentagon 10 sides--decagon
• 6 sides--hexagon 12 sides--dodecagon
• 7 sides--heptagon

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• QUADRILATERALS
• Parallelogram Trapezoid
• (2 pair of parallel sides)
  (1 pair of parallel
  sides)
• (opposite sides are congruent)
• (diagonals bisect each other)
• (opposite angles are congruent)
• Rectangle Rhombus
• (properties of parallelogram
  (properties of parallelogram and
• and has 4 right angles) has
  all sides are congruent)
• (diagonals are congruent (diagonals
  are perpendicular)
• Square
• (properties of parallelogram,
• has 4 right angles, all sides are
  congruent)
• (diagonals are congruent, diagonals are
  perpendicular)

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GEOMETRIC SOLIDS

• are 3-dimensional figures.
• The flat surfaces of the solid are called faces.
• The faces of the solid meet to form line segments
  called edges.
• The corners of a solid are called vertices.
• EDGES Faces Vertices - 2

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POLYHEDRONS

• A polyhedron is a geometric solid whose surfaces
  are formed by polygons.
• The faces of a polyhedron are all polygons.
• A polyhedron does not have any curved surfaces.
• A polyhedron is regular if all of its faces are
  the same size and shape.

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REGULAR POLYHEDRONS

• Tetrahedronhas 4 faces of equilateral triangles
  (also called a pyramid)
• Cubehas 6 faces of squares (also called prism)
• Octahedronhas 8 faces of equilateral triangles
• Dodecahedronhas 12 faces of regular pentagons
• Icosahedronhas 20 faces of equilateral triangles

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AREA

• Area is the amount of surface inside a shape.
  Area is measured in square units such as square
  inches or square centimeters.
• Area of a parallelogram base x height
• Area of a rectangle base x height
• or length x
  width
• Area of a triangle base x height
• 2
• Area of a circle 3.14 x radius x radius

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PERIMETER

• ..is the distance around a shape.
• The perimeter is the sum of all the sides.
• 4 cm
• 3 cm 3
  cm Perimeter 4 cm 3 cm 4 cm 3cm
• 4 cm
  Perimeter 14 cm

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METRIC PREFIXES

• Kilo Hecto Deca m Deci Centi Milli
• l
• g
• King Henry Died Drinking Chocolate Milk.
• To change from one measure to another, simply
  move the decimal point to the right or left.

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METRIC MEASURES

• For length use meters, etc.
• For weight (mass) use grams, etc.
• For volume use liters, etc.

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Metric Measures

• A meter is slightly longer than one yard.
• 1 meter is about 39.37 inches
• 1 inch is about 2.5 centimeters
• 1 kilometer is about 0.6 mile
• 1 mile is about 1.6 kilometers
• A liter is slightly more than one quart.
• 1 liter is about 1.1 quarts
• A gram is about the weight of one paper clip.
• 1kilogram is about 2.2 pounds.