b = 6 mm
Explanation:
To find the missing side of a right triangle, we can use the Pythagorean theorem. This is...
![a^2+b^2=c^2](https://img.qammunity.org/2021/formulas/mathematics/middle-school/96dopf217hvzc3zhswffnjr8l5f26vmjhb.png)
It is important to know that c will always be the hypotenuse, or in this case 10. We can plug everything we know from the picture into the theorem.
![8^2+b^2=10^2](https://img.qammunity.org/2021/formulas/mathematics/middle-school/1quqxoniw7szp5kj2ohxulks3ismml821n.png)
![64+b^2=100](https://img.qammunity.org/2021/formulas/mathematics/middle-school/6ll4bjcek6yjtl8nri6f5pp7cnc58nacd1.png)
Subtract 64 from both sides.
![b^2=36](https://img.qammunity.org/2021/formulas/mathematics/middle-school/5z9e57b86ohuiov6t3d7ih5c87ecgqdtvl.png)
A lot of people make the mistake of thinking the final answer is 36, but since b is squared we need to find the square root of 36.
![√(36)=6](https://img.qammunity.org/2021/formulas/mathematics/middle-school/75nieyu5t139i3jqp37rzru19hmd28clpv.png)
b = 6