Density = m/v
3.86kg=3860g
d= 3860/200
= 19.3g/cm^3
therefore it is gold.
The base is 315. Perimeter of base is 72.
I know there must be an equation to do this, but there is a simpler way.
Just factor number 72 into two numbers which, when multiplied, equal 72. Two of such numbers are 9 and 8, and you can see that the difference between those two numbers is just 1. So that is the answer to your question - the length of the patio is 9 feet, whereas the width is 8 feet.
If you double the width you make a similar prism with a scale factor of two, the surface area of the similar prism will increase as the square of the scale factor
