You're incorrect. an angle of 155 degrees is an obtuse angle. the angle is obviously an acute angle, as it is under 90 degrees. the answer is 50 degrees, or A.
The question "how much space is inside a solid?" is actually asking about the volume of that solid.
The volume of a cone is given by

where h is the height of the cone, and r is its radius.
So, you only need to plug in the values:

Answer:
89.4 in²
Step-by-step explanation:
I'm too lazy to explain.
35 pencils would cost $2.80,
$1.60 / 20 = $.08
Each pencil costs $0.08 each
.08 * 35 = 2.80