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PERIMETER Perimeter (P) is the distance around a polygon. To remember this, think of peRIMeter as the RIM of a figure. To measure perimeter, we can simply (plus) add up the lengths of all the sides. Triangle: p=a+b+c Square: p = 4s Rectangle: p = 2l + 2w where p = perimeter and a, b and c are the lengths of the sides. where s is the length of each side. where l = length and w = width. CIRCUMFERENCE A circle is a closed curved line in a plane, with all points of the line the same distance from a point inside the circle called the center. A circle is named by its center, which is often labeled O. The radius (r) of a circle is a line segment drawn from the center to any point on the circle. (The plural of radius is radii). The diameter (d) of a circle is a line segment drawn from any point on the circle, through the center, to another point on the circle. In any circle, the length of the diameter is twice the length of the radius: d = 2r. The length of the radius is half the length of the diameter: r = d . 2 center radius diameter The circumference (C) of a circle is the distance around. To measure the circumference C of a circle, we use a formula: C d Since d 2r , this formula can also be written as: C 2 r The symbol , or pi, represents an irrational number, 3.1415926….. In calculations with , we use an approximate value: 3.14 or this is an approximation, we use the symbol instead of =. 22 . To show that 7 Perimeter and Circumference Worksheet Name: __________________________ 1. The diameter of a bicycle wheel is 62 centimeters. How far does the bicycle travel when the wheel makes 22 revolutions? Use 3.14 as an approximation for . [A] 1,364 centimeters [B] 194.68 centimeters [C] 8,565.92 centimeters [D] 4,282.96 centimeters 2. 3. A race is held on the track shown. 66 m 9m 9m 9m 24 m 27 m 9m 18 m 15 m What is the total length of the track? Use 3.14 for and round your answer to the nearest meter. Show how you arrived at your answer. 4. A race is held on the track shown. 110 m 15 m 15 m 15 m 40 m 45 m 15 m 30 m 25 m What is the total length of the track? Use 3.14 for answer. and round your answer to the nearest meter. Show how you arrived at your