Please I really need help

Answer:
98yd²
Step-by-step explanation:
Alright, for this you'll need the Pythagorean theorem.
[tex]{a}^{2} + {b}^{2} = {c}^{2} [/tex]
Imagine a right triangle, having twice the given length as the hypotenuse. The legs would be the sides of the square, and therefore be equal.
You can assume it is a square because you're only given half of one diagonal.
Knowing this:
[tex] {a}^{2} + {a}^{2} = {14}^{2} \\ 2 {a}^{2} = 196 \\ {a}^{2} = 98[/tex]
Therefore, the area is 98 square yards.