# How many acute angles can a right triangle have?

To see this, just remember that the sum of the angles of a triangle must be ${180}^{\circ}$. As a right triangle has one angle equal to ${90}^{\circ}$, this means the sum of the remaining two angles must be ${180}^{\circ} - {90}^{\circ} = {90}^{\circ}$.
Thus, both of the remaining two angles must have a measure less than ${90}^{\circ}$ and therefore must be acute.