An isosceles triangle has sides A, B, and C, such that sides A and B have the same length. Side C has a length of 32 and the triangle has an area of 16 . What are the lengths of sides A and B?

1 Answer
Nov 13, 2017

sqrt257~~16.03

Explanation:

First things first - we start off with a diagram!
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Not the most elegant diagram in the world, but it does the job. By convention, the side opposite angle A is a, opposite angle B is b and C is c. h is the perpendicular bisector of AB at M - it cuts AB in half at a right angle.

Let a=b=x. Our job is to find x.

Area_triangle=1/2bh
16=1/2xx32h
16=16h
h=1

Now, we can apply Pythagoras' Theorem in one of the right-angled triangles. We have the height h=1 and the base=16, so we can work out x.

1^2+16^2=x^2
1+256=x^2
x^2=257
x=sqrt257~~16.03