Elementary Algebra

Let x represent the diameter of the circle that we need to find. Now, let’s set up a proportion with the ratio given and a ratio which compares the circumference of the circle to the diameter of the circle. $\frac{22}{7}$ = $\frac{198}{x}$ To solve this equation, we equate the cross products. 22 $\times$ x = 7 $\times$ 198 22x = 1386 Divide both sides by 22. x = 63 The diameter of the circle is 63 centimeters.