The circumference = π x the diameter of the circle (Pi multiplied by the diameter of the circle). Simply divide the circumference by π and you will have the length of the diameter. The diameter is just the radius times two, so divide the diameter by two and you will have the radius of the circle
Equilateral correctly describes pentagon
In a 45 45 90 triangle, the hypotenuse equals the length of the leg multiplied by the square root of 2.
Therefore, x = 6 * square toot (2)
which equals
<span>
<span>
<span>
8.48528</span></span></span>...
Source:
http://www.1728.org/trig2.htm
