Two sisters, Daniel and Sophia, were always rivels when it came to math competitions. One day, Daniel drews a quadrilateral $$ABCD$$ on the floor of his room, with $$AB=8$$. After sneaking into Daniel's room, his sister, Sophia, drew the diagonals of this quadrilateral and labeled their point of intersection as $$S$$. Wanting to challenge Daniel, she measured $$SA, SB, SC,$$ and $$SD$$, and wrote these lengths on the quadrilateral: $$SA=4, SB=5, SC=10, SD=4$$. After doing so, Sophia challenged Daniel to find the length of $$CD^2$$. Find the correct answer Daniel should have given.