Geometry

circle: the set of all points in a place that are the same distance from a given point, called the center of the circle. radios : the distance from the center to a point on the circle. diameter : the distance a cross the circle, through the center. circumference : the distance around a circle. Circumference and Area of Circles

circumference : c=  d or c=2  r area : a=  r2 www.historyforkids.com

1.Find the circumference of the circle. r = 6cm c = 2  r = 2(  ) (6) = 12  = 37.7cm = 38cm scienceray.com

2. Find the area of the circle. 13m r = 13m a =  r2 =  (13)2 = 169  = 531m2 clas.ucsb.edu

3. Find the radios of the circle with a area of 255 square centimeters. a =  r2 255 =  r2 _ _  81 = r2 9cm/81 = r 

3. Find the radios of the circle with a area of 255 square

centimeters.

a =  r2

255 =  r2

_ _



81 = r2

9cm/81 = r