The angle between two vectors is:
CosФ = u - v / Magnitude(u) x magnitude(v)
Magnitude of u = SQRT(7^2 + -2^2) = SQRT(49 +4) = SQRT(53)
Magnitude of v = SQRT(-1^2 +2^2) = SQRT(1 +4) = SQRT(5)
u x v = (7 x -1) + (-2 x 2) = -7 + -4 = -11
cosФ = -11 / sqrt(53) x sqrt(5)
cosФ = -11sqrt265) / 265
Ф =cos^-1(-11sqrt265) / 265)
Ф=132.51 degrees.
Answer:

Converse: Alternate Interior Angles Converse
Step-by-step explanation:
By the Alternate Interior Angles Converse, if
, then l || m.
Use the equation to solve for x as follows:

Subtract 9x from each side


Add 23 to both sides


Divide both sides by 5


Answer: 21599373.37618
Step-by-step explanation:
The answer is 5 planes - we count one for every side.
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