A rectangular parcel of land is 90 ft wide. the length of a diagonal between opposite corners is 30 ft more than the length of the parcel. what is the length of the parcel?

solution:

One leg of the triangle is given 90ft. the other leg of the triangle is x, and the hypotenuse is given as x+30

According to Pythagoras,

C² = a² + b²

So,

(x + 30) = x² + 90²

Use FOIL to expand the binomial:

x² + 60x + 900 = x² + 8100

60x = 7200

X = 7200/60

X = 120