Leticia places a 10 foot ladder against a wall with a 70 degree angle with the ground, how high up the wall does the ladder reach

To solve this problem you must apply the proccedure shown below:
 1. You have that ladder measures 10 foot and forms and angle of 70 degrees with the ground.
 2. Therefore, you have:
 Sinα=opposite/hypotenuse
 α=70°
 opposite=x
 hypotenuse=10
 3. When you substitute the values, you obtain:
 Sin(70°)=x/10
 4. Now, solve for x, as following:
 x=(10)(Sin(70°)
 x=9.39 feet
 Therefore, the answer is: 9.39 feet.

I’m not so sure about this one.