Here is a right triangle with a missing side length what is the missing side length

Right Triangles
A right triangle is recognized because it has an interior angle of 90°.
In right triangles, the Pythagora's Theorem is satisfied.
Being a and b the shorter sides (also called legs) of the triangle, and c the longer side (called hypotenuse), then:
[tex]c^2=a^2+b^2[/tex]The triangle shown in the image has the two legs of values a=15 and b=8. The hypotenuse is c=x, thus:
[tex]x^2=15^2+8^2[/tex]Operating:
[tex]x^2=225+64=289[/tex]Solving for x:
[tex]x=\sqrt[]{289}=17[/tex]x = 17