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Area of Parallelograms and Circles#33
VOCABULARY (circles)
• The decimal representation of pi or starts with 3.14159265 . . . and goes on forever without repeating. Most people estimate using either 3.14 or 22/7.
• Part of a CircleRadius
Circumference C = d, or C = 2r
CenterChord
Diameter
VOCABULARY
• A polygon is a closed figure formed by 3 or more straight lines.
• A parallelogram is a quadrilateral with opposite sides parallel and opposite sides the same length.
• A rhombus is a parallelogram with four equal sides.
• The area of a parallelogram (A=bh) is the product of its base b and its height h.
• The base of a parallelogram can be any one of its sides.• The height of the parallelogram is the perpendicular
distance from the base to the opposite side.• A formula is an equation that shows a relationship
among certain quantities.
You can use the formula for the area of a rectangle to write a formula for the area of a parallelogram. Imagine cutting off the triangle drawn in the parallelogram and sliding it to the right to form a rectangle.
The area of a parallelogram = bh. The area of a rectangle = lw.
The base of the parallelogram is the length of the rectangle. The height of the parallelogram is the width of the rectangle.
FYI
I DO
1)Find the area of the parallelogram.
2) Estimate the area of the circle. Use 3 to approximate .
20 m
8 cm
6 cm
WE DO
1) Find the area of the rectangle..
11 ft.
7 ft.
2) Find the area of the parallelogram.
1 ft14
2 ft12
3) The figure shows a wall of an office with three identical windows. An employee is going to paint this wall of the officeWhat is the area that will be painted?
3 ft
10 ft8 ft
2 ft
4) Find the area of the circle. Use 3.14 for .
yd 8
YOU DO
1) Find the area of the figure.15 in.
9 in.
2) Find the missing dimension of the figure.
3) Estimate the area of the circle. Use 3 to approximate .
9 in.
A=45 in²