Answer:
A. 20,21,29
Step-by-step explanation:
You want to know which of the given sets of numbers is a Pythagorean triple (form a right triangle).
Pythagorean theorem
A set of numbers will form a right triangle if they are a Pythagorean triple.
A set of three integers is a Pythagorean triple if the sum of the squares of the smaller two add up to the square of the largest. The total of numbers in a Pythagorean triple is always even (eliminates choice C).
We can check the values given:
20² +21² = 29²
400 +441 = 841 . . . . . true
This means the triple 19, 20, 29 cannot be a Pythagorean triple.
The set of numbers 20, 21, 29 will form a right triangle.
