29°
triangles can only have 180°
This is a right triangle, so one angle is 90°, leaving us with 90° left
90°-61°= 29°
Answer:
C: Divide both sides by 3
F: Division property of equality
Step-by-step explanation:

The number of people that did not choose math or pe is the same amount of people who chose pe
So before we can find the perimeter, we need to find the hypotenuse. Since this is a right triangle, we can use the pythagorean theorem. The equation for that is
, in which a and b are the legs of the triangle and c is the hypotenuse.
With this info, we can form our equation: 
Firstly, solve the exponents: 
Next, combine everything on the left side: 
Next, square root both sides, and your hypotenuse will be 15 = c.
Now that we have all the triangle side lengths, just add everything up: 
In short, the perimeter is 36 inches.