Home / The area of the circle is $ \pi r^2 = 3.14 \times 5^2 = 3.14 \times 25 = 78.5 $.

The area of the circle is $ \pi r^2 = 3.14 \times 5^2 = 3.14 \times 25 = 78.5 $.

February 22, 2026

$The area of the circle is $ \pi r^2 = 3.14 \times 5^2 = 3.14 \times 25 = 78.5 $.$

A circle has a circumference of 31.4 units. What is its area? (Use $ \pi \approx 3.14 $)
The circumference is given by $ 2\pi r = 31.4 $.
Solving for $ r $, $ r = \frac{31.4}{2 \times 3.14} = 5 $.
The sum of the squares of three consecutive integers is 365. What is the middle integer?
Let the integers be $ n - 1, n, n + 1 $.
Their squares sum to $ (n - 1)^2 + n^2 + (n + 1)^2 = 365 $.