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Find the area of a rectangle whose dimensions are Find the area of a rectangle whose dimensions are 5 3 3 5 Find the area of a rectangle whose dimensions are 5 3 3 5 Find the area of a rectangle whose dimensions are 5 3 3 5 15 square units It takes 15 1x1 tiles to cover the rectangle. Find the area of a rectangle whose dimensions are 5 3 W3 5 L Area = Length x Width A = LW 15 square units It takes 15 1x1 tiles to cover the rectangle. Find the perimeter of a rectangle whose dimensions are 5 3 W3 5 L “measure” Find the perimeter of a rectangle whose dimensions are 5 3 W3 5 L “around” Find the perimeter of a rectangle whose dimensions are 5 3 W3 5 L Find the perimeter of a rectangle whose dimensions are 5 3 W3 5 5 L Find the perimeter of a rectangle whose dimensions are 5 3 W3 5+3 5 L Find the perimeter of a rectangle whose dimensions are 5 3 W3 5+3+5 5 L Find the perimeter of a rectangle whose dimensions are 5 3 W3 5+3+5+3 5 L Find the perimeter of a rectangle whose dimensions are 5 3 W3 5+3+5+3 5 L Perimeter = Length + Width + Length + Width P = 2L + 2W The DIAMETER is the measure across the circle The DIAMETER is the measure across the circle through the center The DIAMETER is the measure across the circle through the center The RADIUS is the measure from the center to any point on the circle The diameter = 2 times the radius d = 2r Wrap the diameter around the circle The diameter fits 3 times plus a little extra. The number is the exact number of “diameters” needed to complete the circle. is approximately 3.14 The measure around the circle (perimeter) is called the circumference. The diameter fits 3 times plus a little extra. The number is the exact number of “diameters” needed to complete the circle. is approximately 3.14 The measure around the circle (perimeter) is called the circumference. The circumference = times the diameter. C = d The diameter fits 3 times plus a little extra. The number is the exact number of “diameters” needed to complete the circle. is approximately 3.14 The are of a circle is the number of square units needed to fill the circle. The following formula gives the area of a circle: A =r2 example: A circle whose radius is 3 units has area 9 28.26 square units <a href = http://www.education2000.com/demo/demo/botchtml/areacirc.htm ></a> Check the web page above to see a visual proof of the area formula example: The circumference of the circle is 10 What is the area of the shaded region?______ The circumference of the circle is 10 What is the area of the shaded region?______ C=d 10 d = 10 r=5 The circumference of the circle is 10 What is the area of the shaded region?______ 10 the area of the square is 100 5 The circumference of the circle is 10 What is the area of the shaded region?______ 10 the area of the square is 100 - the area of the circle is 25 5 The circumference of the circle is 10 What is the area of the shaded region?______ (100 – 25 ) square units 100 – 78.5 = 21.5 square units 10 the area of the square is 100 - the area of the circle is 25