Add the three numbers.
The magical thing about triangles is if they have 3 angles that are the same then 100% they will be the same lengths.
Annnnnd if you open the sum of the 3 angles more than 180degrees then it wouldn’t be a triangle anymore, the lines will open up.
Perimeter is just a fancy way of saying what’s the outside length/distance.
52+30+40 = 122
