Since the bottom shape is a semi-circle, the 3yd is the radius making the triangle's area 7 x 3 / 2 = 10.5
The semi-circle's area is

/2 = 14.14
Combined, you get an area of 10.5 + 14.14 = 24.64
radius = (4*10^2 + 24^2)/8*10 =
(400 + 576)/80=
976/80 = 12.2
diameter = 12.2 x 2 = 24.4
487/67= 7.2686567
rounded= 7.269
Given function : 
We need to identify a " initial amount", b "growth factor", r " rate of growth".
We know, exponential growth formula
, where a is initial amount, b is growth factor. On comparing with given function let us find values of a and b.
⇔
.
We can see a= 1.05 and b = 1.46.
Now, b=1+r.
Therefore, 1+r =1.46.
Subtracting 1 from both sides, we get
1+r-1 =1.46-1
r = 0.46.
On converting 0.46 into percentage, we get
0.46 × 100 = 46.
Therefore, intial amount a = a= 1.05 , growth factor b = 1.46, and the rate of growth r= 46%.