Hello!
We can solve this using trigonometric functions. We will be referring to the 70 degree angle. We need to solve for the hypotenuse. We have the length of the opposite side and need to find the hypotenuse. Therefore, we use the sine.
sin70=12/x
Since we cannot immediately solve for x, we will simplify this equation. We multiply both sides by x.
x(sin70)=12
Divide both sides by sin70.
x=12/sin70
Now we solve this equation.
12/sin70≈15.51
Therefore, x=15.51 cm.
I hope this helps!