Introduction to Perimeter, Circumference, and Area

1
Introduction to Perimeter, Circumference, and Area

• Lesson 1-7

2
Essential questions

• What formulas are common in geometry?

3
Basic geometric formulas

• Area of ANY Quadrilateral (square, rectangle,
  parallelogram, etc.)
• A bh
• The BASE (b) and the HEIGHT (h) are always
  PERPENDICULAR to each other.
• Area of a Triangle
• A ½(bh)
• Perimeter
• The distance around a figure, found by adding the
  individual segment lengths that CREATE the
  figure. Perimeter is a linear measurement,
  one-dimensional.

Area is a two-dimensional measurement, requiring
the multiplication of two measures, the base and
the height!
4
Circle formulas

• Circumference of a circle
• C 2?r
• Area of a circle
• A ?r2
• Some REALLY BIG HINTS ABOUT CIRCLES!
• As big boys and girls, we no longer use d in
  our formulas
• As big boys and girls, we can now RECOGNIZE
  circumference as a linear measure (and therefore
  one-dimensional, hence NO multiplication of
  measure) and AREA as two-dimensional (hence the
  need for SQUARING the ONLY measure available in a
  circle, the radius).

5
Homework

• Page 55 9-29 odd and 41-47 odd (check your
  answers in the back of the book)