The perimeter of a rectangle is 92 feet and its diagonal is 34 feet. find the area of the rectangle.

P=2a+2b=2(a+b),         Area=a*b
diagonal=d
d²=a²+b²

92=2(a+b)---->    46=a+b ------>a=46-b
34²=a²+b² ----->    34²=(46-b)²+b²
34²=(46-b)²+b²
1156=2116-92b+b²+b²
2b²-92b+960=0
b²-46b+480=0
D=46²-4*480=
b=(46+/-√(46²-4*480))/2,
b=(46+/-√196)/2, we take only b=(46+√196)/2=(46+14)/2=60/2=30
b=30
a=46-b=46-30=16
a=16
A=a*b=30*16=480 ft²