Answer: 
Step-by-step explanation:
The complete exercise is: "The circumference of a circle is 47.1 and the diameter of the circle is 15. Which best represents the value of π? "
In order to solve this exercise, it is important to remember that the circle can be calculated with the following formulas:
1. 
Where "C" is the circumference of the circle and "D" is the diameter of the circle.
2. 
Where "C" is the circumference of the circle and "r" is the radius of the circle (Remeber that the diameter is twice the radius).
In this case, the exercise gives you the circumference of the circle and its diameter. These are:

Then, knowing those values, you can substitute them s into the first equation
, as following:

The final step is to solve for
:

Answer:
hey there guys ^^
Step-by-step explanation:
Angles in a triangle total 180°
180=128+5x+10+9x
180-128-10=5x+9x
42=14x
x=3
1:3 is the ratio to boys and girls. I know that 1/4 must be girls. 3/4 will be boys.
Divide 236 by 4.
236/4= 59
Multiply that by 3.
59*3= 177
177 of the students are boys.
I hope this helps!
~kaikers
Answer:
40π in^2
Step-by-step explanation:
360°/72°=5
so, each of the two shaded regions are 1/5 of the circle.
the formula for finding the area of a circle is πr^2, so:
area for one of the shaded regions:
1/5πr^2
1/5π(10)^2
1/5π100
20π in^2
this means that the area for one of the shaded regions is 20π. however, since there are two of them:
2(20π)=40π
so, the area of the shaded regions is 40πin^2