Find the value of x
12
5
X

x = 13

Step-by-step explanation:

Note that the side length x is opposite of the right angle, which means that it is the hypotenuse, which will usually be denoted as c.

Set the equation:

a² + b² = c²

let:

a = 5

b = 12

c = x

Plug in the corresponding numbers (& x) to the corresponding variables:

(5)² + (12)² = (x)²

Simplify. First, solve for the power, and then add:

x² = (5²) + (12²)

x² = (5 * 5) + (12 * 12)

x² = 25 + 144

x² =  169

Next, root both sides of the equation:

√x² = √169

x = √169 = √(13 * 13) = 13

x = 13

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Note the rules, and it should be easier:

30-60-90° = 1 , √3 , 2

45-45-90° = 1 , 1 , √2

Any other measurements use the equation:  a² + b² = c²