Solving for the Diameter (“D”) of a Circle:
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To solve for the diameter of a circle, we start off with the circumference formula because it contains the information we need to Algebraically solve for the Diameter.
Circumference Formula:
C = π • 2(r) or C = π • D, since the Diameter of a circle is 2 times the radius.
We will use the C = π • D formula because it contains the term for Diameter with pi, so we have the proper information to solve for D.
Algebraic Proof:
C = (3.14) • D [Circumference Formula with 3.14 approximate to pi]
(18.85) = (3.14) • D [Given information]
(18.85) / 3.14 = (3.14) • D / 3.14 [Division Property of Equality]
6.003 = D [Division]
D = 6.003 [Symmetric Property of Equality]
Therefore, the Diameter = 6.003 in