If you mean width, 7 x 7 = 49, so 49 feet, then add on the 3.5 feet due to the 0.5 left over, and you have 52.5
Answer:
8.898% will remain after 20000 years.
Step-by-step explanation:
First week need to know the half-life of carbon-14.
In this case it's 5,730 years.
There are calculators available online. (I'm too lazy to run through the equation.) 8.898% will remain after 20000 years.
Angle y is the same as 85 degrees