Answer:The circumference = π x the diameter of the circle (Pi multiplied by the diameter of the circle). Simply divide the circumference by π and you will have the length of the diameter. The diameter is just the radius times two, so divide the diameter by two and you will have the radius of the circle!Hope it helps!!!!
Step-by-step explanation:
Consider right triangle ΔABC with legs AC and BC and hypotenuse AB. Draw the altitude CD.
1. Theorem: The length of each leg of a right triangle is the geometric mean of the length of the hypotenuse and the length of the segment of the hypotenuse adjacent to that leg.
According to this theorem,

Let BC=x cm, then AD=BC=x cm and BD=AB-AD=3-x cm. Then

Take positive value x. You get

2. According to the previous theorem,

Then

Answer: 
This solution doesn't need CD=2 cm. Note that if AB=3cm and CD=2cm, then

This means that you cannot find solutions of this equation. Then CD≠2 cm.
Answer:
A tranlation and a rotaion.
Step-by-step explanation:
In order to map the shapes, you have to translate point A onto point D and then rotate until points C and F, and B and E match up.
Answer:
When we compare the significance level
we see that
so we can reject the null hypothesis at 10% of significance. So the the true mean is difference from 21 at this significance level.
Step-by-step explanation:
Data given and notation
represent the sample mean
represent the population standard deviation
sample size
represent the value that we want to test
represent the significance level for the hypothesis test.
z would represent the statistic (variable of interest)
represent the p value for the test (variable of interest)
State the null and alternative hypotheses.
We need to conduct a hypothesis in order to check if the average age of the evening students is significantly different from 21, the system of hypothesis would be:
Null hypothesis:
Alternative hypothesis:
The statistic is given by:
(1)
Calculate the statistic
We can replace in formula (1) the info given like this:
P-value
Since is a two sided test the p value would be:
Conclusion
When we compare the significance level
we see that
so we can reject the null hypothesis at 10% of significance. So the the true mean is difference from 21 at this significance level.