I think it’s 5 square yards I’m not sure though
8x^2 -3 = 2
add 3 to each side
8x^2 = 5
divide by 8
x^2 =5/8
take the square root of each side
x = +- sqrt (5/8)
X = 2 or -2
either way it’s still 12 , hope this helps !
Outcome
Hope this helps :)
The altitude will be the geometric mean of the lengths, so

. The smaller leg is the hypotenuse of a right triangle sides 4 and

so the usual trig cliche, hypotenuse 8.
Answer: 8