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. <span>Using this formula, 3</span>² + 4² = c² 9 + 16 = c² 25 = c² √25 = √c² 5 = c which if you notice is also the lengthiest .
