Answer:
Base of Island = 15 m, Height = 8 m
Step-by-step explanation:
Here, let the base of the triangular island = b meters
So, the height of the region = (b-7) m
Area of the island = 60 sq.meters
Now, Area of the Triangle 
or, 
or, 120 = b(b-7)
⇒
or, b(b-15)+8(b-15) = 0
⇒(b-15)(b+8) = 0
Solving this, we get either b = 15 m , or b = -8m
But as b is the base of the triangle , so b CANNOT BE NEGATIVE.
⇒ b ≠ -8 m
Hence, Base of Island = b = 15 m
and Height = b -7 = 15 - 7 = 8 m