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2. Given the measures of the sides of a triangle below, which set could form a right triangle?A. 6, 7, 8B. 9, 12, 15C. 12, 15, 20D. 20, 25, 30

User Zhi Wang
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1 Answer

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A Right triangle is a triangle that has an angle whose measure is 90 degrees.

The Pythagorean Theorem states that:


a^2=b^2+c^2

Where "a" is the hypotenuse (the longest side of the Right triangle) and "b" and "c" are the legs of the triangle.

Knowing the above, you can check each set:

Set A


6,7,8

Notice that the longest side is 8. Then:


\begin{gathered} 8^2=6^2+7^2 \\ 64\\e85 \end{gathered}

This set couldn't form a Right triangle.

Set B


9,12,15

The longest side is 15. Then:


\begin{gathered} 15^2=9^2+12^2 \\ 225=225 \end{gathered}

This set could form a Right triangle.

Set C


12,15,20

Knowing that the longest side is 20, you get:


\begin{gathered} 20^2=12^2+15^2 \\ 400\\e369 \end{gathered}

This set couldn't form a Right triangle.

Set D


20,25,30

The longest side is 30. Then:


\begin{gathered} 30^2=20^2+25^2 \\ 900\\e1025 \end{gathered}

This set couldn't form a Right triangle.

The answer is: Option B.

User Valerij Dobler
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