Answer:
![b=\sqrt{c^(2)-a^(2)}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ojeqow38tc4gv8b82k1gu4w76amgvl2s08.png)
Explanation:
To solve the exercise you must solve for b from the formula for the hypotenuse, as you can see below:
- Square both sides of the equation as following:
![c^(2)=(\sqrt{a^(2)+b^(2)})^(2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/2ni8woxzzj0cq3x091h7emyz3fra452lkn.png)
- Now you must subtract a² from each side of the equation, then you obtain:
![c^2-a^(2)=a^(2)-a^(2)+b^(2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/fnolulkaqas4omjyqi3wkc0k5oqfqn0n1e.png)
![c^2-a^(2)=b^(2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/dibg7w3m0kkaqm2xsw36r7inb1n3xv6d03.png)
- Apply square root to both sides:
![\sqrt{b^(2)}=\sqrt{c^(2)-a^(2)}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/905cz3m0dp2j8vmgli6e9awomlqs33suk4.png)
Then:
![b=\sqrt{c^(2)-a^(2)}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ojeqow38tc4gv8b82k1gu4w76amgvl2s08.png)