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10 votes
Which set of numbers form a right triangle?

a. 3.2, 1.3, 2
b. 4, 2.1, 5
C. 5, 13, 12​

User Destan
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2 Answers

11 votes
The answer should be C because if you take the two smaller number, squared them, and add them, they should equal to the biggest number in the least squared.
User Harshit Laddha
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5 votes

Explanation:

Pythagoras must be true :

c² = a² + b²

with c being the Hypotenuse (the side opposite of the 90° angle), and it is always the longest of the 3 sides.

so, the sum of the squares of the 2 smaller numbers must be the square of the largest number.

1.3² + 2² = 1.69 + 4 = 5.69

that is NOT 3.2² = 10.24

so, this is NOT a right-angled triangle.

2.1² + 4² = 4.41 + 16 = 20.41

that is NOT 5² = 25

so, this is NOT a right-angled triangle.

5² + 12² = 25 + 144 = 169 = 13²

so, yes, this is a right-angled triangle.

User Andypaxo
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4.7k points