Appendix A - Review - A.2 Geometry Essentials - A.2 Assess Your Understanding - Page A19: 25

Not a right triangle.

The given sidelengths form a right triangle if they satisfy the Pythagorean Theorem formula $c^2=a^2+b^2$ where $c$ is the longest side (hypotenuses). Substitute all the values into the formula: $(6)^2=(4)^2+(3)^2$ $36=16+9$ $36\ne25$ The sides are NOT equal. Hence, the sides do not represent a right triangle.