By the law of cosines, the angle

satisfies

which reduces to

which converts to approximately 77 degrees (this can be done my multiplying by 180 and dividing by pi).
Answer:
a)
Step-by-step explanation:
The standard deviation is a measure that tells us how far measures tend to be from the mean. A low standard deviation gives us values closer to the mean than a high standard deviation. Usually 68% of the data falls within one standard deviation of the set.
Thus, the most accurate answer would be a) Around 70% of the scores will be located within one standard deviation of the mean
20 ft because the shadow would be 3/2 of the height. 9 is 3/2 of 6 so the height would be 20 bc 30 is 3/2 of 20
Ok soo
-5x+x/2=9
- 4x/2=9
-(2^2-1 *x)=9
2x/2=- 9/2
x=- 9/2
x= -4 1/2