5:10:25. 1+2+5=8÷40=5×1=5. 5×2=10. 5×5=25 so 5:10:25
Let EB and CF be two heights. Then quadrilateral EBCF is rectangle, so BC=EF=5 m. It is given that bases are BC=5 m and AD=11 m. Triangles ABE and DCF are congruent, thus,

Consider right triangle ABE, by the Pythagorean theorem

Answer: 
Y=1/x
y=k/x
Where “k” is a constant
15/2=k/4
2k=60
k=60/2
k=30
:. 15/4=30/x
15x=120
x=120/15
:.x=8.
The longer an object, the longer the shadow they cast at a given time of the day and vice versa. This is called direct proportionality. At the same time,
If 15 foot flagpole ---- casts 11 foot shandow
28 foot tree -------- casts ?? foot shadow
The proportion would therefore be:
Length of shadow cast by tree = (28/15)*11 = 20.533 foot.