By using the Pythagorean Theorem for right triangles, find the length in centimetres. Triangle: B | 5 | 13 | \ C---A Options: A. 8 B. 12 C. 18 D. 65

To find the unknown side of a right triangle using the Pythagorean Theorem, you first need to understand its formula:
a 2 + b 2 = c 2
In this formula, a and b represent the two legs of the right triangle, and c represents the hypotenuse, which is the longest side opposite the right angle.
Given the problem, we have a right triangle with one side (leg) measuring 5 cm, and the hypotenuse measuring 13 cm.
Here are the steps to find the missing leg x :

Identify known values and plug them into the formula:
a = 5 (leg), b = x (missing leg), c = 13 (hypotenuse)
Substitute these into the formula:


5 2 + x 2 = 1 3 2

Calculate squares:
25 + x 2 = 169

Isolate x 2 :
Subtract 25 from both sides:
x 2 = 169 − 25


x 2 = 144

Solve for x :
Take the square root of both sides:
x = 144 ​


x = 12
Therefore, the length of the missing side in centimeters is 12 c m . The answer corresponds to Option (B) 12.

Answered by RyanHarmon181 | 2025-07-21