It took me a minute, but I understand what it wants you to do.
a^2+b^2=c^2
Find the missing length on that one triangle to the left.
62^2+b^2= 99.2^2
Square the numbers.
3844+b^2= 9840.64
Subtract 3844 on both sides.
b^2= 5996.64
Square root it.
b= 77. 437975 round down to b= 77.4
Now, we can find the length of the other missing side. (x+2)
77.4^2+b^2= 112^2
5990.76+b^2= 12,544
Subtract 5990.76 on both sides.
b^2= 6553.24
Square root it.
b= 80.952085, round to b=81
Now, plug that in.
(x+2)= 81
Subtract 2 on both sides.
x=79 (about)
I hope this helps! Make sure to check my work.
~kaikers