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Notes 7.4 A/B Circumference. Sir. Circumference. The distance AROUND a circle. * a circle’s perimeter * distance a circle will travel Formula for Circumference : C = d · π -or- C = 2 π · r. Finding radius & diameter using circumference. Use inverse operations!
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Circumference • The distance AROUND a circle. * a circle’s perimeter * distance a circle will travel Formula for Circumference: C = d · π -or- C = 2 π · r
Finding radius & diameter using circumference • Use inverse operations! C = d · π -or- C = 2 π· r So… d= C ÷ π -or- r = C ÷ 2 π
Pi • For all circles the ratio of circumference to diameter (C/d) is always π. • π has a value of 3.14 or 22/7
AREA • Area = π·r²
Applying our new knowledge!!! • Which formula will correctly calculate the circumference of the four circles? 60 units 60 units