Question

Need help please and thank you

Answer 1

Using pythagorean trplet

$\\ \sf\longmapsto AC^2=AB^2+BC^2$

$\\ \sf\longmapsto AC^2=6^2+8^2$

$\\ \sf\longmapsto AC^2=36+64$

$\\ \sf\longmapsto AC^2=100$

$\\ \sf\longmapsto AC=\sqrt{100}$

$\\ \sf\longmapsto AC=10$

Answer 2

Use the Pythagorean theorem:
a^2+b^2=c^2
Let the unknown hypotenuse be x:
6^2+8^2=x^2
36+64=x^2
100=x^2
x=10
The answer is the first choice: 10