(a)
A right angle sums to 90
6x + 4x + 10 = 90
10 x = 80
x = 8
(b) straight line = 180
5x + 13 + 3x + 7 = 180
x = 20
(c) Sum of triangle angles = 180
3x + 5 + 2x + 18 + 2x + 17 = 180
x = 20
(d) Sum of two angles in right angle = 90
90 = x + 30
x = 60
B. 9*10^16 (because in question give it)
B. 3*10^9 (because answer to first question is divided by seconds in one year (365*24*60*60).
Answer: Choice A) cone
One way to picture this is to think of a propeller. As the propeller spins, it carves out a 3D space even though the blade is "2D" in a sense.
If we spin everything around segment BC, we get a 3D cone forming. The base of the cone is vertical and it has a radius of AC. The height of the cone is segment BC. It might help to rotate the paper 90 degrees clockwise so that BC is vertical.
