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Pearson Geometry Common Core, 2011

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Pearson Geometry Common Core, 2011 View details

6. Law of Cosines

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Exercise 29 Page 532

Do you remember the formulas for finding circumference?

3.8

Practice makes perfect

The circumference C of a circle with radius r is calculated using the formula below. C=2π r We know that the circumference of a circle is 24mm. To find the radius, let's substitute 24 for C in the formula, and solve the equation for r.

C=2π r

C= 24, π= 3.14

24=2( 3.14) r

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Solve for r

Multiply

24=6.28r

.LHS /6.28.=.RHS /6.28.

3.821656...=r

Rearrange equation

r=3.821656...

Round to 1 decimal place(s)

r≈3.8

Subchapter links

Lesson Check p.529

Practice and Problem-Solving Exercises p.530-532

Standardized Test Prep p.532

Mixed Review p.532