Working with Shapes in Two Dimensions

1
Working with Shapes in Two Dimensions

• Two-Dimensional Objects

2
Perimeter

• The distance around a figure.
• Think of perimeter as the distance you would
  travel if you walked around the edge of the
  figure.
• To find the perimeter, add the lengths of the
  sides of the figure.

3
Area

• When working with flat figures you can calculate
  how much surface is enclosed within the
  boundaries.
• Area is measured with square units such as
  square inches, square feet, and square meters.
• Formulas are used to calculate total area of a
  figure.

4
Rectangle

• Has four sides and four right angles. Opposite
  sides of each pair are parallel and the same
  length.
• To calculate the area of a rectangle multiply the
  length times the width.
• l x w

5
Square

• A square has 4 sides, all the same length, and
  four right angles. Opposites sides of each pair
  are parallel.
• To calculate the area of a square multiply the
  length of one side times itself
• (side squared)

6
Parallelogram

• Has four sides. Opposite sides of each pair are
  parallel and the same length.
• To calculate the area of a parallelogram multiply
  base times the height.
• b x h

7
Right Triangle

• Triangle has three sides with one right angle.
• To calculate the area of a triangle, multiply
  one-half times the length of the base times the
  height.
• 1/2bh

8
Trapezoid

• Has four sides. Only one pair has parallel
  opposite sides.
• To calculate the area of a trapezoid multiple ½,
  add the bases, and multiply by the height.
• ½ (b1 b2)h

9
Circle

• A circle is formed by points that are all the
  same distance away from a certain point
• To calculate the area of a circle multiply pi
  times radius squared.
• Pi(r)2