Answer:
A: adjacent angles: The angle ∠CFD & ∠DFE are directly next to each other, making them <em>adjacent angles</em>.
B: Complementary angles: Note that m∠BFC measures at 90°. m∠BFE is a straight line, with 180°. This means that ∠BFE - ∠BFC = ∠DFE.
180 - 90 = 90 ∴ m∠DFE = 90°
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Remember that the surface area of an object is the area of all of its faces added up.
The area of one circle is:

The area of the rectangle is a little more complex. We are missing the length of one side, which is the circumference of one of the base circles (think about when the diagram above is made into a three-dimensional cylinder). The circumference of the circles is:

The area of the rectangle is thus:

When all of the areas are added together, we find that the total surface area of the shape is:

Sorry I don’t think I know that
Answer:
The equation of plane is

Step-by-step explanation:
We have to find the equation of plane passing through the point (0,-1,1) and orthogonal to the planes

Thus, we can write:

We will evaluate:
![n = n_1\times n_2\\\\n = \left[\begin{array}{ccc}i&j&k\\3&4&-3\\-3&2&4\end{array}\right] \\\\n = i(16 + 6)-j(12-9) +k(6+12)\\n = 22i-3j+18k\\n =](https://tex.z-dn.net/?f=n%20%3D%20n_1%5Ctimes%20n_2%5C%5C%5C%5Cn%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Di%26j%26k%5C%5C3%264%26-3%5C%5C-3%262%264%5Cend%7Barray%7D%5Cright%5D%20%5C%5C%5C%5Cn%20%3D%20i%2816%20%2B%206%29-j%2812-9%29%20%2Bk%286%2B12%29%5C%5Cn%20%3D%2022i-3j%2B18k%5C%5Cn%20%3D%20%3C22%2C-3%2C18%3E)
The required plane passes through the point (0,-1,1)
Thus, the equation of plane is

is the required equation of the plane.