Em uma escola, estudam em tres periodos 1256 meninas e 1593 meninos. quantos alunos estudam nessa escola?

I will answer in English.

This can be translated to:

In a school, 1256 girls and 1593 boys study in three periods. how many students study at that school?

This means that we have a total of:

(1256 + 1593) students = 2849 students, divided in 3 periods.

So the total number of students in that school is 2849

And the number of students per period is:

2849/3 = 949.7

Because we can only have whole numbers here, we can say that in each period there are around 950 students.

x = central angle apc = measure of minor arc ac

the two angles x and 30 add to 180, so x+30 = 180 and x = 180-30 = 150. the measure of minor arc ac is 150 degrees.

what we need to do from here is find the circumference and then multiply it by x/360 since there are 360 degrees in a circle. in this case, x = 150, so x/360 = 150/360 = 15/36 = 5/12. the shortest distance along the curve from a to c is 5/12 of the distance around the entire circle (aka circumference)

c = circumference

c = pi*d

c = pi*24

c = 24pi

now multiply this by 5/12 to get

distance along minor arc ac = (5/12)*(circumference)

distance along minor arc ac = (5/12)*(24pi)

distance along minor arc ac = 10pi

the formula you can use is

l = (x/360)*pi*d

with

l = length of minor arc

x = central angle

d = diameter

which essentially is the steps we took though a bit differently.