Question

What is the circumference of the circle that circumscribes a triangle with side lengths 3, 4, and 5?

Answer 1

Answer:

  5π, about 15.708 units

Step-by-step explanation:

A 3-4-5 triangle is a right triangle. When a circle circumscribes a right triangle, the hypotenuse is the diameter of the circle. The circumference of a circle is given by ...

  C = πd

For a diameter of 5 units, the circumference is ...

  C = π(5) = 5π = 15.708 . . . units

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Additional comment

The (3, 4, 5) triple is one of the first Pythagorean triples you run across. It is the smallest integer triple, and the only primitive triple with values in an arithmetic sequence. You can show this is a Pythagorean triple by ...

 3² + 4² = 9 +16 = 25 = 5²

That is, these numbers satisfy the Pythagorean theorem relation for sides of a right triangle.