ISEE Upper Level Math : How to find the length of the side of an acute / obtuse isosceles triangle

Study concepts, example questions & explanations for ISEE Upper Level Math

varsity tutors app store varsity tutors android store

Example Questions

Example Question #1 : Isosceles Triangles

Two sides of an isosceles triangle have lengths 3 feet and 4 feet. Which of the following could be the length of the third side?

Possible Answers:

Correct answer:


An isosceles triangle, by definition, has two sides of equal length. Having the third side measure either 3 feet or 4 feet would make the triangle meet this criterion.

3 feet is equal to  inches, and 4 feet is equal to  inches. We choose 36 inches, since that, but not 48 inches, is a choice.

Example Question #1 : How To Find The Length Of The Side Of An Acute / Obtuse Isosceles Triangle

The triangles are similar. Solve for .


Possible Answers:

Correct answer:


Because the triangles are similar, proportions can be used to solve for the length of the side:


Learning Tools by Varsity Tutors

Incompatible Browser

Please upgrade or download one of the following browsers to use Instant Tutoring: