The hypotenuse (side C) of a triangle is 13 inches long. Which of the following pairs of measurements could be the correct for the lengths of the other two sides of the triangle? (Note: A2 + B2= C2)
A. 5 inches, 12 inches
B. 2.5 inches, 6 inches
C. 2.5 inches, 4 inches
D. 5 inches, 8 inches
In this problem, we take the triangle as a right-angled triangle and label it as follows:
From the Pythagoras theorem A2 + B2= C2, we can look for a combination of A and B that when the squares of A and B are summed give a square of 13. Mathematically,
But C=13 inches
If we take A=5 inches and B=12 inches, then
Next, we take A=2.5 inches, B=6 inches
Next, we take A=2.5 inches, B=4 inches
6.25+16=169
22.25≠169
Taking A=5 inches and B=8 inches
From the above computation, the combination of A=5 inches and B=12 inches give a triangle with a hypothenuse of 13 inches.
Therefore, the Correct Answer is A.