Notice that the given right triangle has a marked angle measuring 60^(∘). Therefore, by the Triangle Angle Sum Theorem the measure of the third angle must be 30^(∘).
We found that the length of a shorter leg is 7. Also, in a 30^(∘)-60^(∘)-90^(∘) triangle, the longer leg is sqrt(3) times the length of the shorter leg.
y=sqrt(3) * 7=7sqrt(3)
