A decagon has 10 sides (think decade and decathlon). From the center of the decagon we draw the radii and in doing so we take the area of the decagon and divide it into 10 congruent Triangles.
The angles around the center add up to 360 because they form a circle and since there are 10, they each measure 36 degrees. So the answer to the first part (the angle between the radii) is 36 degrees.
Each of these triangles has two equal sides (both radii) so is Isosceles. That means that the base angles are congruent. So the two angles that are left in each triangle must measure the same. Since the angles in a triangle add up to 180 degrees, we know that the two remaining angles are together equal to 180-36=144 degrees. Since they are equal in measure they each measure 72 degrees.
Thus the answer to the second part, trhe measure of the angle between a radius and the side of the polygon is 72 degrees.
Am I too late to answer this
Answer:
X=67.5
Step-by-step explanation:
3X + X=4X
4X+90=360
4X=360-90
4X=270
X=67.5
Answer:
The test statistic is 
Step-by-step explanation:
We are interested in determining whether or not the proportion of the student who experience anxiety during the exam is significantly more than 80%.
At the null hypothesis, we test if the proportion is 80%, that is:

At the alternate hypothesis, we test if the proportion is more than 80%, that is:

The test statistic is:

In which X is the sample mean,
is the value tested at the null hypothesis,
is the standard deviation and n is the size of the sample.
80% is tested at the null hypothesis:
This means that 
A random sample of 100 students was taken. Eighty-five of the student in the sample experienced anxiety during the exam.
This means that 
The test statistic is



The test statistic is 
Answer:
I believe the answer is C :)
Step-by-step explanation: