Hi there!
The formula to find the are of a circle is :
a = r²
The formula to find the circumference of a circle is :
c = 2r
In order to use the area formula, you need to figure out what the radius (r) is.
If we solve for "r" in the circumference equation, we have :
r = c ÷ (2)
Now we use this to replace "r" in the area formula :
a = ( c ÷ (2))²
When we simplify this we get :
a = c² ÷ 4
Now you can put your value of "c" into this equation and find "a".
*Remember, is about 3.1416.
Solving for "a" :
a = c² ÷ 4
a = 28² ÷ 4
28² = 28 × 28 = 784
a = 784 ÷ 4
4 = 4 × = 12.56637061435917
a = 784 ÷ 12.56637061435917
a = 62.38873769202297cm²
You need to round to the nearest square centimeter, which means that you need to round to the nearest whole number :
a = 62cm²
There you go! I really hope this helped, if there's anything just let me know! :)
Answer:
?
Step-by-step explanation:
Answer:
A
Step-by-step explanation:
-4u - w = u + 6w
-4u = u + 7w (Add w to both sides)
-5u = 7w (Subtract u from both sides)
w = (Divide both sides by 7)
<h3>
Answer: 100 meters</h3>
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Explanation:
If you draw out the diagram, then you'll find that a 45-45-90 triangle forms. The nice thing about this type of triangle is that the two legs are always the same length. The horizontal leg is 100 meters, so the vertical leg must also be 100 meters.
Side note: this type of triangle is an isosceles right triangle.
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You could use the tangent rule to get the same thing
tan(angle) = opposite/adjacent
tan(45) = 100/x
1 = 100/x
1*x = 100
x = 100
In this case, the opposite leg is the vertical leg since it is furthest from the angle of elevation.
Since you'd didn't specify what place value I'm assuming it's the whole number so the answer is: 80,000,000