Use trigonometry and triangle congruency rules to find X
Answer:
Ok to find the surface area of this cylinder first we need the circumference to find this we do C=πd
C=3.14*18
C=56.52
now we have to multiple this by the height of two
113.04
now we have to find the area of the bottom to do this we do A=πR^2
A=3.14*81
A=254.34
multiple this by two for the two sides we get
508.68
now we add this to 113.04 we get
621.72
since I used 3.14 instead of more digits of pie we can round this up so the answer is C.
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BIFFY OUT!!!
Answer:
The correct answer is Y = 26
A cube, is made off 6 squarial faces, so all faces on that cube, are squares, the front, back, left, right, top and bottom.
a square has all equal sides, and also all right angles, so all angles in a square are 90°. Let's say the sides are "x" long.
now, if we run a plane on that cube diagonally, check the picture below, the diagonal side at the bottom, by usin the 45-45-90 rule as you see it there, will be x√2.
let's keep in mind that, "x" is opposite side of that angle θ, and then x√2 will be the adjacent side of it.
and we can use those two to get the tangent and then the inverse tangent to get the value, as you see it in the picture.
if you need the angle in radians, run the inverse tangent again, just make sure your calculator is in radians mode.