Chapter 8 - Geometry - 8.8 Pythagorean Theorem - 8.8 Exercises - Page 592: 33

Unknown length of the triangle is $\approx 8.1$ cm.

Let $x =$ unknown length of the triangle $a^{2} + b^{2} = c^{2}$ $x^{2} + 8.2^{2} = 11.5^{2}$ $x^{2} + 67.24 = 132.25$ $x^{2} = 65.01$ $x = \sqrt 65.01$ $x = 8.062...$ $x \approx 8.1$ cm