Answer:
10cm ( A )
Explanation:
This would use the Pythagorean Theorem. That means it would be -
a^2_b^2= c^2, in this case, you have 2 of your legs already so those two values would be a&b. you would stick those two into the equation and it should look like this:
6^2+8^2=c^2
then 36+64=c
and then 100=c
after that, you would take the square root of c to get
10!