Question

A triangle has a perimeter of 36 inches. The combined length of two of the sides is 21 inches. What is the length of the third side in inches?

Answer 1

To determine the length of the third side of a triangle, subtract the combined length of the other two sides from the perimeter. With a perimeter of 36 inches and two sides totaling 21 inches, the third side measures 15 inches.

Step-by-step explanation:

To find the length of the third side of a triangle, knowing the perimeter and the combined length of two sides, you can use a simple subtraction. If the perimeter of a triangle is 36 inches and two of the sides combined equal to 21 inches, you subtract the combined sides from the total perimeter to find the length of the third side:

Perimeter (P) - sum of two sides = length of third side

36 inches - 21 inches = 15 inches.

Therefore, the third side measures 15 inches in length.

Answer 2

Sure, let's solve for \(x\):

\[21 + x + \text{length of the third side} = 36\]

Combine like terms:

\[x + \text{length of the third side} = 15\]

Now, subtract \(x\) from both sides:

\[\text{length of the third side} = 15 - x\]

So, the length of the third side is \(15 - x\) inches.