Leon states that 21 , 28 , 35 is a Pythagorean triple because the lengths found in step 2 form a Pythagorean triple. Which explains whether or not Leon is correct?

The lengths 21, 28, and 35 are 7 times 3, 4, and 5, which form a Pythagorean triple. Multiplying every length in a Pythagorean triple by the same whole number preserves the relationship, so Leon is correct: multiplying every length by the same whole number results in a Pythagorean triple.

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