The legs of a right triangle are 3 and 4 inches long how long is the hypotenuse

In the right angled triangle, a hypotenuse is the longest line of the triangle and is always the one that is opposite the right-angle of the triangle.

If your triangle is a right angled triangle, the simplest way is to use the Pythagora's Theorem to find the length of the hypotenuse. The formula for which is

a² + b² = c² where c is the unknown hypotenuse and a and b are the other two sides.

Using this formula,

3 ² + 4² = c²

9 + 16 = c²

25 = c²

√25 = √c²

5 = c which if you notice is also the lengthiest.