I think it’s 20
Hope this helps
10 + f = 10
-10 -10
f = 10 - 10
f = 0.
For a polygon to be regular it must have all sides the same length and all interior angles the same.
Answer: 60 degrees
Explanation: the angles of a triangle sum to 180 degrees, and all the angles in an equilateral triangle are the same so every angle in an equilateral triangle must equal 60 degrees.
