Which of the following is the reciprocal of 5

C

Step-by-step explanation:

The reciprocal is always the number flipped over.

E.g. reciprocal of 9 is 1/9 and the reciprocal of 1/9 is 9

C. 1/5

Step-by-step explanation: To find the reciprocal, divide

One by the number given.  

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

1/5^2 = 7.56/45