The hypotenuse c = 101, length of a = 99 and length b = ?.
\Apply pythagorean theorem:
.
(Substitute a = 99, and c = 101)
Evaluate powers:
.

Apply subtraction property of equality: a = b then
.
(Subtract 9801 from each side)
Apply commutative property of addition: a + b = b + a.
\
(Apply additive inverse property:
)
(Subtract:
)
Apply square roots property:
then
.
(Evaluate square roots:
)
The positive value of 
The length of
. \ \