2. What is perimeter?
PERIMETER is the distance (or length) around a
shape!
You can find it by adding the lengths of the sides.
12
Perimeter =
9 9 12 + 9 + 17 +
9=
47
17
3. Finding the Perimeter of a Shape on
a Graph
Find the perimeter of
triangle ABC.
Point A = (-5, 4)
Point B = (1, -2)
Point C = (3, 6)
So if we find the lengths (distances)
of AB, BC, and AC, we can add them
to get the perimeter!
4. Finding Distances
Point A = (-5, 4) Point B = (1, -2) Point C = (3,
6)
Length AB = √(1 - -5)2 + (-2 – 4)2
√(6)2 + (-6)2
√(36 + 36) = √72 = 6.4
Length BC = √(3 – 1)2 + (6 - -2)2
√(2)2 + (8)2
√(4 + 64) = √68 = 6.2
You try Length AC!
5. Finding the Perimeter
To find perimeter: ADD all the sides.
Perimeter = AB + BC + AC
Perimeter = 6.4 + 6.2 + 6.2
Perimeter = 18.8
