Using Pythagorean Theorem to find a missing side

In a right triangle find the length of the side not given.
b = 1 and c = √5 and a = ?

Pythagorean Theorem is a² + b² = c² 
- the sum of the squares of the legs is equal to the square of the hypotenuse

b = 1, c = √5, a = ?
a² + (1)²  = (√5)²  {substituted into the pythagorean theorem}
a² + 1 = 5  {squared 1 and squared √5}
a² = 4  {subtracted 1 from both sides}
a = 2  {took the square root of both sides, accepting only positive √4, since it is a measurement)

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