The radius of a circle is 9 in . Find its circumference in terms of \( \pi \)

To find the circumference of a circle, you use the formula \( C = 2\pi r \), where \( r \) is the radius. In this case, the radius is 9 inches. Plugging in the value, you get \( C = 2\pi \times 9 \) which simplifies to \( C = 18\pi \) inches. So, the circumference is \( 18\pi \) inches. In the world of art, the concept of circles appears in designs, architecture, and logos. Think about famous circular structures, like the Colosseum in Rome or a beautifully designed wheel on a bike! Understanding how to calculate circumference helps not only in math but also in creating balanced and pleasing designs that use circular elements effectively. A common mistake when calculating circumference is to confuse radius with diameter. Remember, the diameter is twice the radius, so if you mistakenly use the diameter in the formula, you'll end up with an incorrect value! Always double-check which measurement you are using to avoid this pitfall!