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Question from Amanda, a parent:
what is the area of a circle with a circumference of 3000 metres?
Amanda,
The area of a circle is given by the formula A = π r2, where A is the area and r is the radius. The circumference of a circle is C = 2 π r.
If we "solve for r" in the second equation, we have r = C / (2 π ). Now we use this to replace r in the first equation: A = π [ C / (2 π ) ]2.
When we simplify this, we get A = C2 / (4 π).
Now you can put your value of C into this equation and find A. Remember, π is about 3.1416.
Important:
The sum of the three angles inside
every triangle is always 180°.
First, look at the left triangle alone.
Two of its angles are 46° and 58° . (46° + 58° ) = 104°
That leaves (180° - 104° ) = 76° degrees for the third angle.
The third angle in that triangle is 'x'.
x = 76° .
At the point where 'x' and 'z' come together:
'x' and 'z' are a "linear pair".
Placed side-by-side, they form a straight line.
So (x + z) = 180° .
But x = 76°.
So z = (180° - 76°). z = 104° .
Now look at the the skinny triangle on the right alone.
The angle at the top is 13°, and z = 104°.
(13° + 104°) = 117° .
That leaves (180° - 117°) = 63° for the third angle.
'y' is the third angle.
y = 63° .
Answer: $4 senior, $7 child
Step-by-step explanation:
(3s + 9c = 75)
8s + 5c = 67
X=23 First, you have to subtract 12 by 12 to cancel it out. Next, you have to do the same thing to 20.05. 20.05 minus 12 is 8.05. All you have left is .35x. To get rid of the this you have to divide .35x by .35. Now all you have left is x. Finally you have to do the same thing to 8.05. 8.05 divided by .35 is 23. So, x=23
