# Math Help - the vertex of the triangle to be equilateral

1. ## the vertex of the triangle to be equilateral

A triangle has two vertices at ( -a, 0 ) and (a , 0 ). What must be the third vertex of the triangle to be equilateral?

Thanks

2. ## Re: the vertex of the triangle to be equilateral

Originally Posted by rcs
A triangle has two vertices at ( -a, 0 ) and (a , 0 ). What must be the third vertex of the triangle to be equilateral?
The third vertex will be $(0,b)$ where the distance $\mathcal{D}[(0.b);(a,0)]=2|a|$

3. ## Re: the vertex of the triangle to be equilateral

Originally Posted by rcs
A triangle has two vertices at ( -a, 0 ) and (a , 0 ). What must be the third vertex of the triangle to be equilateral?
... note that half an equilateral triangle is a 30-60-90 special right triangle.