Answer:The area is 14306. 625 cm.
Step-by-step explanation:
To find the area of the circle, we will need to find the diameter and find the radius.
So we know the circumference is 423.9 m and we know to get the circumference, you will need to multiply pie by the diameter .
so now we need divide the circumference by pie to find the diameter.
423.9/ 3.14 = 135 so 135 is the diameter.
To find the radius we need to divide the diameter by 2.
135/2 = 67.5
Now is time to find the area which uses the formula A= nr^2
A = 3.14 * 67.5^2
A = 14306. 625
Answer:
The diameter will increase at a rate of 1/30π cm/min
Step-by-step explanation:
Here we want to calculate the rate at which the diameter will increase
Mathematically, the area of a sphere is given as;
A = 4πr^2
But r = d/2
so A = 4 * π * d/2 * d/2 = πd^2
dA/d(d) = 2πd
Thus dd/dA = 1/2πd = 1/2 * π * 15 = 1/30π
Given dA/dt = 10
Mathematically;
d(d)/dt = d(d)/dA * dA/dt
dd/dt = 1/30π * 10 = 10/30π = 1/3π cm/min
Hello from MrBillDoesMath!
Answer:
75
Discussion:
A plane triangle has 180 degrees. Using this in the diagram gives
x + 81 + angle BAC = 180 (***)
(The diagram is a bit fuzzy but I think the above numbers are accurate)
The diagram also shows that (156 + angle BAC )= 180 as a straight line has 180 degrees. So
angle BAC = 180 - 156 = 24
Substituting this in (***) above gives
x + 81 + 24 = 180 =>
x + 105 = 180 => (as 81 + 24 = 105)
x = 180 107 = 75
Check: Does
x + 81 + angle BAC = 180 ?
75 + 81 + 24 = 180. Yes
Thank you,
MrB
