Write this ratio in its simplest form: the ratio of the circumference of a circle to its radius.
Our ratio is circumference to radius. The circumference in terms of the radius is equal to two times the radius times 𝜋. The radius is then equal to 𝑟. With this ratio, we notice that we have an 𝑟 on either side.
Imagine that we divide both sides of our ratio by the radius. On the left, it would cancel out, leaving us with two 𝜋. On the a right, we would have radius divided by radius, 𝑟 over 𝑟.
We would then simplify that value to one. In its simplest form, the ratio of the circumference of a circle to its radius is two 𝜋 to one. For every one unit of radius, there is two 𝜋 units in the circumference.