Incorrect. First, triangles can be classified according to their sides: scalene (no congruent sides), isosceles (two congruent sides), or equilateral (three congruent sides). Second, triangles can be classified according to their angles: acute (all three angles less than $\displaystyle{{90}}^{\circ}\usepackage{cmbright}\Huge\$ ), right (contains a $\displaystyle{{90}}^{\circ}\usepackage{cmbright}\Huge\$ angle) , or obtuse (contains an angle that is greater than $\displaystyle{{90}}^{\circ}\usepackage{cmbright}\Huge\$ and less than $\displaystyle{{180}}^{\circ}\usepackage{cmbright}\Huge\$ ).