Answer:
SU = 3.5
Step-by-step explanation:
We have the triangle 30° - 60° - 90°.
Right triangles with 30-60-90 angles will have their ratio of the sides as
1 : √3 : 2 (look at the picture).
We have:
SR : SU : RU = 1 : √3 : 2
Therefore RU = 2SR and SU = SR√3.
We have RU = 4. Substitute:
2SR = 4 divide both sides by 2
SR = 2
SU = 2√3 ≈ 2(1.73) = 3.5
