Answer:
a = 7.21
Explanation:
Remark
This just uses a^2 + b^2 = c^2. You know 2 of the three things there.
Givens
Solution
a^2 + b^2 = c^2 Substitute the givens
a^2 + 12^2 = 14^2 Expand
a^2 + 144 = 196 Subtract 144 from both sides
a^2 = 196 - 144 Collect like terms on the right
a^2 = 52 Take the square root of both sides.
sqrt(a^2) = sqrt(52)
a = 7.2111
a = 7.21 Answer