Exam Review Part 3

Radius - distance from the center of a circle to the edge, represented by the variable "r".

Diameter - The distance from across a circle through it's center. Represented by "d".

Relationship between radius and diameter? The radius is half of the diameter and the diameter is twice the radius.

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Constructing Circles:

1. compass
2. trace a circle
3. string

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Practice:

• Diameter if radius is 6 : 12
• Radius if diameter is 9: 4.5

Now try these:

-What is the radius id diameter equals 10?

-If you multiply your diameter from the first question and divide by 2, what would the radius make?

-What if the radius was 3 and you doubled, what would be the diameter?

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Pi

- the ratio of the circumference of a circle to it's d

iameter.

- approximate value is 3.14

- pi = c/d

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Formulas:

d = 2r 2r = d r = d/2 d/2 = r

(pi) d = c c/(pi) = d c = (pi) d

2 (pi) r = c c/(pi) = 2r c = 2(pi) r

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Thanks for reading!

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Bye! GOOD LUCK AT MATH EXAMS!