Chapter 9
Math 7
Class Notes
Perimeters of Polygons
Perimeters of Regular Polygons
Vocabulary
Geometry
| o
| The study of points, lines, angles, surfaces, and solids |
Parallel
| o
| Lines that are always the same distance apart; parallel lines never meet |
Polygon
| o
| A closed, many-sided figure that is made up of line segments |
Quadrilateral
| o
| A polygon with four sides |
Rectangle
| o
| A four-sided polygon with four right angles and the opposite sides equal |
Rhombus
| o
| A four-sided polygon with two pairs of parallel sides having the same length |
Regular Polygon
| o
| A polygon in which each side and each angle has the same measure |
Scalene Triangle
| o
| A triangle with no equal sides |
Isosceles Triangle
| o
| A triangle with two equal sides |
Equilateral Triangle
| o
| A triangle will all three sides equal |
Perimeter
| o
| A measure of the distance around a figure or shape |
ADD ALL SIDES
EXAMPLES
Make sure to show the formula used and each step to receive full credit.
Label, label, label
| 1.
| Find the perimeter of a quadrilateral with sides measuring |
3 inches, 4 inches, 5 inches, and 6 inches.
P = a + b + c + d
P = (3) + (4) + (5) + (6)
P = 18 inches
** IMPORTANT**
Notice in this example that 4 different variables are used, this shows that there are four different numbers being substituted in.
| 2.
| Find the perimeter of a square with |
sides measuring 6 centimeters.
(HINT: Square has 4 equal sides)
P = s + s + s + s P = 4s
P = (6) + (6) +(6) +(6) P = 4(6)
P = 24 centimeters P = 24 centimeters
**IMPORTANT**
| 1.
| When all sides are equal, the same variable is used |
| 2.
| Two different ways of doing the problem, |
by four as a short-cut
Textbook pages: 238 - 245
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