Appendix A - Review - A.2 Geometry Essentials - A.2 Assess Your Understanding - Page A19: 13

26

Since we have a right triangle with legs $a$, $b$ and the hypotenuse $c$, then by the Pythagorean theorem, we have $$c^2=a^2+b^2.$$ Thus, the hypotenuse is given by $$ c=\sqrt{a^2+b^2}=\sqrt{10^2+24^2}=\sqrt{676}=26 .$$