0.28 = 7/25
0.84 = 21/25
Hope this is the answer you were looking for.
AC is the diagonal of the square.
To find the side length use Pythagorean Theorem.
a^2 + a^2 = 28^2
2a^2 = 784
a^2 = 392
a = sqrt 392
Perimeter = 4a where a is the length of the side
P = 4Sqrt392
P = 79.2 millimeters
76 Im pretty sure but im not 100 percent sure i remember this
Whats the angle inside the triangle