14 units
By find the missing angle to be 60. Use Cos = a/h
Cos60 = 7/h
x h, then ÷ by cos60
h = 7/cos60
h = 14
Hypotenuse is the longest length
Soh Cah toa
So, the last length must be 7 root 3 (12.12 to 2d.p)
(root means square root)
Hope this helps!
