A circle with a circumference 20 has an arc with a 72 degree central angle

25.13 units

Step-by-step explanation:

Please be sure to specify what you are looking for.  IN this case it's the arc length.

Formula for arc length:  s = rФ, where Ф is the central angle in radians (not degrees).

Here, s = (20 units)(72π/180) = (20 units)(1.26) = 25.13 units

the sum of all the angles in a triangle are equal to 180

so you can add   the 3 given angles together to equal 180:

5y + 2y + 2y = 180

or since all three angles have the same letter, combine the 3 angles to equal 180:

9y = 180

f(x) = - 2/3x + 5; f(5/2)

substitute 5/2 in for x:

f(5/2) = -2/3(5/2) + 5

simplify the right side:

f(5/2) = -5/3 + 5

f(5/2) = 10/3

answer:

f(5/2) = 10/3

i hope this you!