The sides 6, 8 and 10 make a right triangle since they are a pythagorean triple.
Other Explanation: If you use two sticks, one 6 inches and one 8 inches and place the perpendicular to each other (like a capital L ) then place a stick 10 inches long from the exposed end of the 6-in stick to the exposed end of the 8-in stick, you will get a right triangle with the sides 6, 8, and 10.
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