Answer:
Circumference ≈ 82.9
Step-by-step explanation:
The formula for calculating the circumference of a circle is:
C = 2πr
Where 3.14 is pi (as stated on your screen)
And r is the radius.
Knowing this substitute those values
C = 2(3.14)(13.2)
Multiply 2 and 3.14.
C = (6.28)(13.2)
Multiply 6.28 and 13.2.
C = 82.9 when rounded.
A few ways. you can enter it into a calculator for one, but the easiest way would be to reference a unit circle and look for an ordered pair where sin (the y value), is equal to -1/2
on a unit circle, the sin value is -1/2 at 7pi/6 and 11pi/6
because sin is the y value, it will additionally be in the quadrants III or IV based on the fact that (-1/2) as a sin value IS a negative and would have to be found in a quadrant in which sin is negative (the lower half of a coordinate plane, in this case)