The answer would be 20
A squares sides are equal and there are 4 of them so you take 80 (the total perimeter) and divide that number by 4 (number of sides) and you get 20
The length of a median is equal to half the square root of the difference of twice the sum of the squares of the two sides of the triangle that include the vertex the mediam is drawn from and the square of the side of the triangle the median is drawn to.
triangle sides by a, b, c.
ma=122c2+2b2−a2
mb=122c2+2a2−b2
mc=122a2+2b2−c2
