The formulas for arc length and area of a sector are quite close in their appearance. The formula for arc length, however, is related to the circumference of a circle while the area of a sector is related to, well, the area! The arc length formula is

. Notice the "2*pi*r" which is the circumference formula. The area of a sector is

. Notice the "pi*r squared", which of course is the area of a circle. In our problem we are given the arc length and the radius. What we do not have that we need to then find the area of a sector of the circle is the measure of the central angle, beta. Filling in accordingly,

. Simplifying by multiplying by 360 on both sides and then dividing by 36 on both sides gives us that our angle has a measure of 60°. Now we can use that to find the area of a sector of that same circle. Again, filling accordingly,

, and

. When you multiply in the value of pi, you get that your area is 169.65 in squared.
In scientific notation, you want (a number less than 10 and more than 0) times 10^x
so 48978 made so that it is less than 10 and more than 0 is
4.8978
we count how many times we divided 48978 by 10 to get 4.8978 and we get 4
so 4.8978 times 10^4
or on an online test
4.8978e+04
C. (4,-7)
y=2x-15
-7=2(4)-15
4x+3y=-5
4(4)+3(-21)=-5
9514 1404 393
Answer:
x^2/9 +(y +2)^2/49 = 1
Step-by-step explanation:
For center (h, k), and x- and y-semi-axis lengths a and b, respectively, the equation is ...
((x -h)/a)^2 +((y -k)/b)^2 = 1
The given ellipse has center (0, -2) and semi-x-axis length 3 and semi-y-axis length 7. Thus the equation is ...
(x/3)^2 +((y +2)/7)^2 = 1
This might conventionally be written as ...
x^2/9 +(y +2)^2/49 = 1