Presentation Transcript
Slide 1:1 This pool measures 25 ¼ feet by 80 feet.
What is the perimeter of the pool?
Objective :2 Objective Solve real-world problems involving area and perimeter.
Determining Perimeter :3 Determining Perimeter
Slide 4:4 Equation:
P = 15 + 12 + 13
P = 30 m Tom is going to put a fence around his rock garden. His garden is in the shape of a triangle with the sides measuring 15 m, 12 m and 13 m.
How much fence does he need?
Slide 5:5 6 + 7 + 8 + 8 = P
P = 29 inches
Finding the Area? :6 Finding the Area? How do you find the area of a square?
How do you find the area of a rectangle?
How do you find the area of a triangle?
Formulas :7 Formulas Triangle = ½ x base x height
Rectangle = length x width
Square = s2
Area of a Triangle :8 Area of a Triangle Calculate the area of each triangle. 5 cm 3 cm 10 ft 12 ft 13 ft 13 ft 4 cm
Area of a Rectangle :9 Area of a Rectangle Calculate the area of each rectangle.
4 ft
7 m
12 ft
5 m
Area of a Square :10 Area of a Square Calculate the area of the square.
Area of a Square :11 Area of a Square Calculate the area of each square. 2 cm
Area of a Rectangle :12 Area of a Rectangle Calculate the area of the rectangle by
multiplying length times width.
A = L × W
= 9 × 3
= 27 cm2
Area of a Triangle :13 Area of a Triangle Area = ½ × base × height height base base height
Area of a Triangle :14 Area of a Triangle Area = ½ × base × height 10 in 4 in 6 m 8 m A = ½ × 6 × 8
= 3 × 8
= 24 m2 A = ½ × 4 × 10
= 2 × 10
= 20 in2
Triangle vs. Rectangle :15 Triangle vs. Rectangle Base = length Height = width Area of Triangle = ½ of Area of Rectangle
= ½ (L × W) or ½ (base × height)
Example :16 Example A typical size for a photograph is
8 × 10 inches.
What is the area of the photo?
Example :17 Example Mr. Liddle is re-painting his chalkboard and
needs to know its area in order to buy enough
paint. His chalkboard is 4 ft tall and 6 ft long.
What is the area of the chalkboard?
Demonstration :18 Demonstration Marie is making a quilt by cutting fabric squares
diagonally across into triangles.
What is the area of each triangle created from a
4-inch square? 4 in 4 in 4 in
Demonstration :19 Demonstration Area of triangle = ½ × base × height
= ½ × 4 × 4 = 8 in2