You may recognize that ∆WYZ is a 3-4-5 right triangle. Without any work, then
c = 5
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If you don't remember that a right triangle with legs 3 and 4 has a hypotenuse of 5, you can compute it using the Pythagorean theorem.
c² = 3² + 4²
c² = 9 + 16 = 25
c = √25 = 5
