The circle shows the radius of 12mm what is the circumference

24π or about 75.4 mm

Step-by-step explanation:

The circumference of a circle is denoted by C = 2πr, where r is the radius.

Here, we see that r = 12, so plugging this in:

C = 2πr

C = 2π * 12 = 24π ≈ 75.4 mm

The answer is thus 24π or about 75.4 mm.

~ an aesthetics lover

x^2 + 81

we can factor this using difference of square binomials.

rewrite the equation:

x^2 - (-81)

factor:

(a^2 - b^2) = (√a^2 + √b^2)(√a^2 - √b^2)

(x^2 - (-81) = (x + √-81)(x - √-81)

we can remove the - from under the radical by multiplying it by i.

(x^2 - (-81) = (x + i√81)(x - i√81)

(x^2 - (-81) = (x + 9i)(x - 9i)

we can check our answer by using foil:

x^2 - 9ix + 9ix - 81i^2

x^2 - 81^2

i^2 = -1

x^2 + 81