CIRCLES AREA AND CIRCUMFERENCE VOCABULARY Perimeter The measure

CIRCLES AREA AND CIRCUMFERENCE

VOCABULARY Perimeter • The measure of the distance around a figure (distance around the outside) Area • The number of square units needed to cover a surface or figure

VOCABULARY Pi • Circumference divided by diameter

VOCABULARY Circumference • Perimeter of a Circle (outside of a circle) Radius • Distance from edge of circle to the center Diameter • Distance from one side of the circle to the other THROUGH THE CENTER

CIRCUMFERENCE Circumference = perimeter of a circle C = 2(3. 14)r • r = radius • C = circumference C = (3. 14)d • d = diameter

AREA A = 3. 14 r 2 = 3. 14 (4) 2 = 3. 14(16) A = 50. 24 cm 2 4 cm

circumference diameter radius DIAGRAM

HELPFUL INFORMATION Diameter = 2 x Radius d = 2 r

PRACTICE PROBLEM Clinton purchased a circular rug to cover part of a floor. The diameter of the rug is 8 feet. What area of the floor will the rug cover?

RECTANGLES AND SQUARES AREA AND PERIMETER

RECTANGLES Area: The space inside of a figure Perimeter: Distance around the outside l = length w = width To find area: Multiply length and width SQUARE UNITS (cm 2) To find perimeter: Add up all of the sides OR NORMAL UNITS (cm)

SQUARES To find area, take a side and square it s = side length SQUARE UNITS To find perimeter, take a side and multiply it by 4 NORMAL UNITS

PRACTICE PROBLEM Dana has a rectangular garden that she wishes to fence in. If the dimensions of the garden are 15 feet by 13 feet, what is the minimum amount of fencing that she needs to enclose her garden?