y/3 = h
Multiply both sides by 3:
y = 3h
We know that
The Euler's formula state that, the number of vertices, minus the number of edges, plus the number of faces, is equal to two
V - E + F = 2
clear F
F=2-V+E
in this problem
V=8
E=14
F=?
so
F=2-8+14
F=8
the answer is8 faces
The answer is -12
these are the steps on how to find that
-2x2y
-2(-3)2(y)
6 times -2
-12
Actually, the answer is not A, if you're saying A is the first choice above. That's incorrect. You will need to use the Geometric mean for right triangles here to figure out what the value of a is. We will use this form:

. We have a value for YZ of 3; side a is XZ. That means in order to solve this we need WZ, which we can find using pythagorean's theorem. 3^2 + 4^2 = c^2 and 9 + 16 = c^2 and c = 5. Now we fill in accordingly:

. Cross-multiply to get 3XZ=25 and side XZ is

. XZ is 25/3 and YZ is 3, so 25/3 - 3 = XY. That means that XY (side a) = 16/3 or 5 1/3, choice B, or the second one down.
There are 360 degrees in a circle
10x+5+140+45+2+11x=360
21x+192=360
21=168
X=8
Eb would be the same as the central angle
80+5=85