What is the circumference of the circle below?
52 yd
A 254.18 yd
B 387 yd
C 199.3 yd
D 163.28 yd

D) 163.28 yd

Step-by-step explanation:

to get the circumference, the equation is 2(π * radius)

52 is the diameter, and half of a diameter is the radius.

so the radius of your circle is 26.

now put that into the equation and you get 2(26π), or 52π

pi is infinite, but you can actually get away with multiplying 52 by 3.14, which gives you the approximate answer.

52 * 3.14 = 163.28

so your answer is D) 163.28 yd

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.