Answer is 40. A triangle equals 180 so all you do is subtract 65 and 75 from 180 to get your answer.

Let

The curl is

where
denotes the partial derivative operator with respect to
. Recall that



and that for any two vectors
and
,
, and
.
The cross product reduces to

When you compute the partial derivatives, you'll find that all the components reduce to 0 and

which means
is indeed conservative and we can find
.
Integrate both sides of

with respect to
and

Differentiate both sides with respect to
and




Now

and differentiating with respect to
gives




for some constant
. So

Answer:
14130 ft^3
Step-by-step explanation:
The formula for the volume of a cone of radius r and height h is
V = (1/3)*pi*r^2*h.
Here, V = (1/3)(3.14)(15 ft)^2*(60 ft) = 20*3.14*225 ft^3 = 14130 ft^3