A. 4 yards hope this helped!!!
Look at the picture.

For XY and ZX use the Pythagorean theorem.


The perimetero fo XYZ:

Answer: sin
= ±
Step-by-step explanation:
We very well know that,
cos2A=1−2sin²A
⟹ sinA = ±
As required, set A =
& cos a=
,thus we get
sin
=±
∴ sin
=±
= ±
since ,360° <
<450°
,180° <
<225°
Now, we are to select the value with the correct sign. It's is obvious from the above constraints that the angle a/2 lies in the III-quadrant where 'sine' has negative value, thus the required value is negative.
hope it helped!
Let unknown integer be n.
So then your sentence would translate to 3n² + n = 2.
If you need to solve for n then we can move 2 to left side by subtract both sides by 2:
3n² + n - 2 = 0
Now you can factor:
3n² + 3n -2n - 2 = 0
3n( n + 1 ) - 2( n + 1 ) = 0
( 3n - 2 )( n + 1 ) = 0
3n - 2 = 0 OR n + 1 = 0
3n = 2 OR n = -1
n = 2/3 OR n = -1
Final answer: n = 2/3 OR n = -1