ok so to find the sum of interior angles the formula is
s=180(n-2)
s is sum and n is the number of sides
so this is a quadrilateral cause it has 4 sides
because of that n=4
substitute
s=180(4-2)
now you can either distribute or do pemdas but its easier and more efficient to just do pemdas
s=180(2)
s=360 degrees
