Answer:
Step-by-step explanation:
Time for first race 57.9seconds
x=time for first half of race
x-4.7=second half of race
Equations is
x + (x-4.7)=57.9
2x-4.7=57.9
2x=57.9+4.7
2x=62.6
x=31.3
Check answer
31.3 + (31.3-4.7)=57.9
31.3 +26.6=57.9
57.9=57.9
Answer:
The answer would be B
Step-by-step explanation:
C=2(pi)r
C=25.12
Do you need the fraction? I don’t understand what you are asking
Answer:
all the angles of the pentagon do not add up to 540
Step-by-step explanation:
total degree in a shape
180 × (n-2) where n is the number of side
a pentagon has 5 sides so
180 × (5-2)
= 540
100+105+72+126+127= 530
all the angles of the pentagon do not add up to 540
The percentage of the semicircle shaded section is approximately 23,606 %.
The percentage of the area of the semicircle is equal to the ratio of the semicircle area minus the half-cross area to the semicircle area. In other words, we have the following expression:

(1)
Where:
- Area of the half cross, in square centimeters.
- Area of the semicircle, in square centimeters.
- Percentage of the shaded section of the semicircle.
And the percentage of the shaded section is:
![r = \left[1-\frac{4 \cdot (2\,cm)^{2}+4\cdot \left(\frac{1}{2} \right)\cdot (2\,cm)^{2}}{0.5\cdot \pi\cdot (16\,cm^{2}+4\,cm^{2})} \right]\times 100](https://tex.z-dn.net/?f=r%20%3D%20%5Cleft%5B1-%5Cfrac%7B4%20%5Ccdot%20%282%5C%2Ccm%29%5E%7B2%7D%2B4%5Ccdot%20%5Cleft%28%5Cfrac%7B1%7D%7B2%7D%20%5Cright%29%5Ccdot%20%282%5C%2Ccm%29%5E%7B2%7D%7D%7B0.5%5Ccdot%20%5Cpi%5Ccdot%20%2816%5C%2Ccm%5E%7B2%7D%2B4%5C%2Ccm%5E%7B2%7D%29%7D%20%5Cright%5D%5Ctimes%20100)

The percentage of the semicircle shaded section is approximately 23,606 %.
We kindly invite to check this question on percentages: brainly.com/question/15469506