Answer:
15cm
Step-by-step explanation:
First, a square's diagonal is basically the hypotenuse of a 45-45-90 triangle. a 45-45-90 triangle has a really special relationship, where the side length is x, and the diagonal is x 
. So, the side length is 15.
Digit in ones place- 8
Digit in tenths place- 2
The 3 inside angles need to equal 180 degrees.
Angle K is given as 48 degrees.
Angle M would be 90 degrees.
Angle J = 180 - 90 - 48 = 42
Angle J = 42 degrees
