Question

Help me please I'm really stuck

Answer 1

Use pythagorus, a² + b² = c²

in this case you have c and either a or b. (it doesn't matter which, i'll use a)

using a bit of algebra, you can turn your formula into b = $\sqrt{(c² - a²)}$

now all you have to do is plug in your numbers. a = 6mm and c = 9mm

b = $\sqrt{((9)² - (6)²)}$ = $\sqrt{(81 - 36)}$ = $\sqrt{45}$ ≈ 6.7mm

Answer 2

Use the Pythagorean theorem a^2+b^2=c^2
6^2+9^2=c^2
36+81=c^2
117=c^2
find the square root of 117
the answer is  11