The ASVAB Tutor Presents the Answer to a Right Triangle Question

Mathematics Knowledge Answer

Yesterday I presented a question on Mathematics Knowledge.  The question is a geometry question that focuses on right triangles.

The question is:

What is the hypotenuse of a right triangle with 2 sides of 30 and 40?

A. 50

B. 60

C. 70

D. 80

This problem can be solved using the Pythagorean theorem.  A right triangle has two short sides called legs and a long side called a hypotenuse.  In this triangle, the legs are 30 and 40.  The hypotenuse is unknown.

The Pythagorean theorem is c² = a² + b²

c² = 30² + 40²

c² = 900 + 1600

c² = 2500

c = 50

The hypotenuse in this triangle is 50.

The answer is Choice A. 50.

Another way to answer this is to memorize the common right triangles.

The common right triangles are triangles with the following measurements.

3:4:5         5:12:13

6:8:10     10:24:26

The triangle in the question is 30:40:50 which is ten times bigger than the common right triangle measuring 3:4:5.