The answer is 14.87.
a^2+b^2=c^2
10^2+11^2=c^2
100+121=c^2
221=c^2
Square root both sides
14.87=c
Hope this helps!!
The formula is X=8. hope it helps
2(x)+2(2x)=126
this is because one side is equal to x, and the other side is equal to 2x. then to get the perimeter, you multiply each side by by two and then add those two numbers together.