Presentation on theme: "Area of Parallelograms and Circles #33. VOCABULARY (circles) The decimal representation of pi or starts with 3.14159265... and goes on forever without."— Presentation transcript:
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 Circle Radius Circumference C = d, or C = 2r Center Chord 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 ft 1 4 2 ft 1 2 3) The figure shows a wall of an office with three identical windows. An employee is going to paint this wall of the office What is the area that will be painted? 3 ft 10 ft 8 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