Question

the radius of a circle is 15.6 cm. find the circumference to the nearest tenth.

Explanation:

Step1: Recall the formula for the circumference of a circle

The formula for the circumference \(C\) of a circle is \(C = 2\pi r\), where \(r\) is the radius of the circle.

Step2: Substitute the given radius into the formula

Given \(r=15.6\) cm. Substitute \(r = 15.6\) into \(C = 2\pi r\). So \(C=2\times\pi\times15.6\).

Step3: Calculate the value

\(C = 31.2\pi\). Using \(\pi\approx3.14159\), then \(C\approx31.2\times3.14159\).
\(31.2\times3.14159=(30 + 1.2)\times3.14159=30\times3.14159+1.2\times3.14159\)
\(30\times3.14159 = 94.2477\), \(1.2\times3.14159=3.769908\)
\(C\approx94.2477+3.769908 = 98.017608\)

Step4: Round to the nearest tenth

To round \(98.017608\) to the nearest tenth, look at the hundredth digit. The hundredth digit is \(1\). Since \(1\lt5\), we keep the tenth digit as it is.

Answer:

\(98.0\) cm