Explanation:
Distance formula to find distance from O to Q is sqrt (306)
Distance from R to P = sqrt (34)
Diagonals ( found above) intersect at right triangles in a rhombus
so you can break it into two right triangles of base = sqrt (306)
and height sqrt (34)/2
TWO triangles of area = 1/2 base * height
TOTAL Area is then : TWO * 1/2 ( sqrt(34)/2)* sqrt (306) = 51 units^2