An <em>imaginary number</em>. The defining property of an imaginary number is that has the number i attached to it, where i² = -1.
A few examples of imaginary numbers: 3i, i, -7i, (√3)i, (1/2)i
Let the width of the rectangle be x
Then length =x-4
Area=x(x-4)=140
x²-4x=140
x²-4x-140=0
x²-14x+10x-140=0
x(x-14)+10(x-14)=0
(x-14)(x+10)=0
Therefore,length=14 cm and width=10 cm
Well to get the area of 288 the dimensions would be a couple of things but 16 ft by 18 ft seems to work, so the dimensions increase by 4 ft on each side.
12+4=16
14+4=18
18*16=288
The tree was approximately 40.8ft tall.
You use the equation, a^2+b^2=c^2.
12^2 + 39^2 = x^2, add the results of 12^2 and 39^2 to make 1665 = x^2. You can take the positive root of both sides, 3√185, and it equals 40.80441152, which is rounded to 40.8.
