interior angle of a regular 18-gon.
It is easier to calculate the exterior angle of a regular polygon of n-sides (n-gon) by the relation
exterior angle = 360/n
For a 18-gon, n=18, so exterior angle = 360/18=20 °
The value of each interior angle is therefore the supplement, or
Interior angle = 180-20=160 degrees.
Naming of a 9-gon
A polygon with 9 vertices is called a nonagon (in English) or enneagon (French ennéagone, but the English version is sometimes used)
You had a good start with the correct answer.
Exterior angle of a 15-gon
The exterior angle of a 15-gon can be calculated using the relation given in the first paragraph, namely
Exterior angle = 360/15=24 degrees
The number of T-shirt bought by Shilpa from a clothing store = 30
Percentage of T-shirt that were blue = 20%
Then Number of T-shirt that were blue in color = (20/100) * 30
= 2 * 3
= 6
Number of T-shirts that were black in color = (1/2) * 30
= 15
Then
The total number of T-shirts that were black and blue = (15 + 6)
= 21
Then
The total number of T-shirts that were neither black nor blue = 30 - 21
= 9
So the number of T-shirts that were neither black nor blue was 9.
Answer: $6.54
Step-by-step explanation:
The price of one orange is $1.09
The price of 4 oranges is $3.64
The price of 6 oranges is $6.54
There are a total of 297 students in the 7th grade. Rough estimates would say that about half of that number are boys and half are girls. Asking only 50 random girls would be biased because not only would it not be all of the girls (the number of girls would be around 148 or 149) but it would also be ignoring the roughly 148 to 149 boys there are on estimate. The sample would be biased because it would be ignoring the opinions of more than half the seventh grade.
