47inches in Cm. is C. 119.38cm
Answer:
The answer is 
Step-by-step explanation:
Assuming the snowball is a perfect sphere, then if A denotes the surface area and D the diameter then:

Differentiating wrt r we have:

We are told that
and we want to find 
By the chain rule we have:

∴
∴
When D=10 then

The sign (-) shows that the D is decreasing.
Answer:
As shown in picture, this is a trapezoid.
The area of a trapezoid is calculated by:
A = (base1 + base2) x height x (1/2)
To work out A, we need to find out base1, base2, and height.
base1 = YZ = 
base2 = XW =
Otherwise, the height (distance between base1 and base2) is 4 as shown in picture.
=> A = (3 + 7) x 4 x (1/2) = 20
Hope this helps!
:)
The standard form would be y = 7x^2 - 42x + 67