Which expression can be used to determine the side length of the rhombus?
The answer is the first option: 10/Cos(30°)
Explanation:
1. As you can see in the figure attached, there is a right triangle and its hypotenuse (which is represented with the letter "x") is the side you want to calculate. So, you have:
Cos(α)=Adjacent leg/Hypotenuse
α=30°
Adjacent leg=(20 in)/2=10 in
Hypotenuse=x
2. When you substitute these values into the formula, you obtain:
Cos(α)=Adjacent leg/Hypotenuse
Cos(30°)=10/x
3. Therefore, you obtain the expression to determine the side length of the rhombus by clearing the hypotenuse "x", as below:
x=10/Cos(30°)