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Ch 1.9 Standard 8.0 : Students know, derive, and solve problems involving perimeter, circumference, and area. Standard 10.0 : Students compute areas of polygons, including rectangles. Objective: 1) To find perimeters of rectangles and squares, and circumferences of circles.
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Ch 1.9Standard 8.0: Students know, derive, and solve problems involving perimeter, circumference, and area.Standard 10.0:Students compute areas of polygons, including rectangles. Objective: 1) To find perimeters of rectangles and squares, and circumferences of circles. 2) To find areas of rectangles, squares, and circles.
Perimeter The perimeterP of a plane figure is the sum of the side lengths of the figure.
Example (Perimeter) 1) Find the perimeter of the rectangle. = 2(6) + 2(4) = 12 + 8 = 20 in. 2) Find the perimeter of a square with s = 3.5 in. P = 4s = 4(3.5) = 14 in.
Circumference The circumferenceC of a circle is the distance around the circle which can be calculated using the formula: C = πd or C = 2πr
Example (Circumference) Find the circumference of a circle with radius 14m. = 2π(14) = 28π 88.0 m
Area The areaA of a plane figure is the sum of the areas of its non-overlapping parts.
Example (Area) 1) Find the area of the rectangle. = (6 in)(4 in) = 24 in2 2) Find the area of a square with s = 3.5 in. A = s2 A = (3.5)2 A = 12.25 in2
Area of a Circle The areaA of a circle is the sum of the areas of its non-overlapping parts which can be calculated using the formula: A = πr2 Example: Find the area of a circle with radius 8 cm. A = πr2 = π(8)2 = 64π 201.1 cm2