Simplify ½ of (3/4 -1/4)

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angles. measure need asap

What can you determine about the solutions of this system

The diagonals of a quadrilaretral intersect at (-1,4). one of the sides of the quadrilateral is bounded by (2,7) and (-3,5) determine the coordinates of the other side in order for the quadrilaretral to be a square.