Answer:
21
Step-by-step explanation:

multiple both sides by 7
v = 21
Check:
21/7 = 3
3 = 3
Cosine is a trigonometric function. The value of cos(x+π), when the value of cos(x)=-(√3)/2 is √3/2. The correct option is A.
<h3>What is a cosine?</h3>
Cosine is the trigonometric function equal to the ratio of the side next to an acute angle to the hypotenuse in a right-angled triangle.
Given the value of cos(x)=-(√3)/2, therefore, the value of x can be written as,
cos(x) = -(√3)/2
(x) = cos⁻¹ [-(√3)/2]
x = 5π/6 = 150°
Now, the value of cos(x+π) will be,
cos(x+π)
= cos[(5π/6)+π]
= cos(11π/6)
= √3 / 2
Hence, the value of cos(x+π), when the value of cos(x)=-(√3)/2 is √3/2.
Learn more about Cosine function here:
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I think a but I said I think but iam not sure I looked it up its b
Answer:
Two pairs of parallel sides
All sides congruent
Four right angles