## Elementary Geometry for College Students (5th Edition)

An equilateral triangle has all three angles at 60$^{\circ}$. This is because every triangle's angles add up to 180$^{\circ}$, and equilateral means that all three sides and angles are the same. Therefore, 180$^{\circ}$ $\div$ 3 = 60$^{\circ}$. A right triangle has one angle at 90$^{\circ}$. 90 $\ne$ 60, so this "equilateral right triangle" does not exist and you cannot draw it.