First of all, let's recall the area of a triangle, knowing its base (b) and height (h):

The exercise is showing you that, if you inscribe a polynomial with more and more side, the area of the polynomial will approximate the area of the circle better and better (you can see youself that the polygon is "filling" the circle more and more as the number of sides increase).
Now, the second column tells you the area of each of the triangles the polygon is split into. So, we can see that the first polygon is split into 3 triangles, each of them having base 1.73 and height 0.5.
So, the area of each triangle is

There are three of these triangles, so the area of the whole polygon is

In the second case, you have six triangles, each with base 1 and height 0.87. So, the whole area is

Finally, in the last case you have 8 triangles, each with base 0.77 and height 0.92. So, the whole area is

Let f be the fathers age and let s be the sons age
f = 60 s = 30
when f = 45
s = 15 which is only a third if his fathers age
when f = 40
s = 10 which is a quarter of his fathers age
therefore when his father was 4 times his age, the son was 10
Answer:
(0,0) or Infinitely many solutions.
Step-by-step explanation:
-−4x−4y=0
−4x−4y+4y=0+4y(Add 4y to both sides)
−4x=4y
−4x/-4= 4y/-4
(Divide both sides by -4)
x=−y
4x+4y=0
4(−y)+4y=0
0=0
Answer: 25/4=6.25
Explanation:
4w=25
w=25/4=6.25
(I am assuming that the circles and the block are equal, some of the picture got cut off.)
Answer:
75
Step-by-step explanation:
48% of snowstorms caused power outages, which means 52% did not.
Therefore, 39 is 52% of all snowstorms.
39 = 0.52x
x = 75
There were 75 snowstorms over the 5-year period.