What is the length of the hypotenuse of a right triangle if the two other sides are of lengths 5 and 4?

1 Answer
Jun 23, 2018

#approx 6.4031# units

Explanation:

Given a #triangle ABC# where #angle A# is a right angle and opposite sides are labeled #a, b and c# respectively, then Pythagoras' Theorem states that:

#a^2 = b^2+c^2#

Since the hypotenuse of a right triangle is the side opposite the right angle, in this example, the hypotenuse #=a# and either #b=5 and c=4# or vice versa. (Which makes no difference in this case]

#:. a^2 = 5^2+4^2#

#= 25 + 16 = 41#

Hence, #a = +-sqrt41 approx +-6.4031#

Since the side of a triangle must be positive,

#-> a approx 6.4031# units