125.6
Area of a circle = πr^2
Area of circle 1 = 3.14 × 11 × 11
=379.94cm^2
Area of circle 2= 3.14 × 9 ×9
=254.64cm^2
Area of a shaded region
=379.94cm^2 - 254.64cm^2
=125.60cm^2
Answer:
90°
Step-by-step explanation:
angle on a straight line=180 and half of 180=90°
Complete question :
The 100m dah times in the girl's track meet were normally distributed with a mean of 13 seconds and a standard deviation of 0.3 seconds.
Lana finished the race in 13.2 seconds . If 84 other girls ran in the event, approximately how many runners did she beat?
Answer:
21 runners
Step-by-step explanation:
Mean, μ = 13 seconds
Standard deviation, σ = 0.3
Lana's race time = 13.2
We find the proportion of runners who had race time above 13.2 ;
Proportion of who had race tune above 13.2
P(x > 13.2)
Obtain the Zscore
Zscore = (x - μ) / σ
Z = (13.2 - 13) / 0.3
Zscore = 0.2 / 0.3 = 0.6667
P(Z > 0.6667) = 0.25239 (Z probability calculator)
This is about 0.25239 * 100 = 25.24% = 25% (nearest percent)
Hence, Number of runners Lana beat = 25% of total runners ;
0.25 * 84 = 21
Hence, Lana beat about 21 runners
Use the law of cosines to solve for angle A. Plug your known side length values into the equation a^2 = b^2 + c^2 – 2bc cos A.
Then use the law of sines to find angle B. (Sin A/a = Sin B/b = Sin C/c).
Because the two red angles within B are congruent, divide your angle measure in half.
From there, do the law of sines to solve for x. Good luck!
I hopes this helps
I think it’s A I’m not sure
