## Trigonometry 7th Edition

We will use given data about triangle ABC and Pythagoras Theorem to solve for 'a- We know that - $c^{2} =a^{2} + b^{2}$ ( Pythagoras Theorem) Therefore - $a^{2} =c^{2} - b^{2}$ $a^{2} = (13)^{2} - (12)^{2}$ $a^{2} = 169 - 144$ $a^{2} = 25$ therefore $a = \sqrt (25)$ a = 5