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Important Info. You’ll need: notebook, pencil, and formula card. Pause. Rewind. Volume. Questions? Area & Perimeter Area: Covering Perimeter: Surrounding Polygons: Triangles, Rectangles, Squares, Parallelograms, Trapezoids What is a circle? Not a polygon. A plane figure with three or more straight sides and angles. Definition: a closed plane figure made up of all the points the same distance from a point called the center. F G E H radius EF = EG = EH Circle E F ½ E ½ diameter EF + EI = IF I Circle E radius + radius = diameter r+r=d 2r = d Things You Should Know... Radius (Plural: Radii) Diameter A straight line from the center of a circle to it circumference. A straight line passing through the center of a circle connecting 2 points on the circumference. It is half of the diameter. It is twice the radius. Radius = r Diameter = d Circumference Distance around a circle. C=2πr or C=πd π = 22/7 ≈ 3.14 Finding Circumference C=2πr Use this formula when you are given the radius. C=πd Use this formula when you are given the diameter. Find the circumference of each circle. Use 3.14 for π. 4 cm Find the circumference of each circle. Use 3.14 for π. 6 in Find the circumference of each circle. Use 3.14 for π. Find the circumference of each circle. Use 3.14 for π. Questions Email: [email protected] [email protected] [email protected] Before school tomorrow. Extra help on Mondays and Wednesdays.