Again, a^2+b^2=c^2
c=10
b=9
10 squared is 100
9 squared is 81
100-81=19
The square root of 19, rounded to the nearest hundredth, is 4.36
Answer:
69.81 sq. m. (rounded to 2 decimal places)
Step-by-step explanation:
The sector of a circle is "part" or "portion" of a circle. The formula for the area of a sector is:
Where
is the central angle
r is the radius
Given the figure, the arc is given as 80 degrees, but not the central angle of the shaded sector. But from geometry we know that the central angle and the intercepted arc have the same measure. So we can say:
Also, the radius of the circle shown is 10 meters, so
r = 10
Now, we substitute in formula and find our answer:
Thus,
The area of the shaded sector is 69.81 sq. meters.
Explanation:
It helps to understand the process of multiplying the binomials. Consider the simple case ...
(x +a)(x +b)
The product is ...
(x +a)(x +b) = x² +(a+b)x + ab
If the <em>constant</em> term (ab) is <em>negative</em>, the signs of (a) and (b) are <em>different</em>.
If the constant term (ab) is <em>positive</em>, the signs of (a) and (b) will both match the sign of the coefficient of the linear term (a+b).
___
Of course, the sum (a+b) will have the sign of the (a) or (b) value with the largest magnitude, so when the signs of (a) and (b) are different, the factor with the largest magnitude will have the sign of (a+b), the x-coefficient.
<u>Example</u>:
x² -x -6
-6 tells you the factors will have different signs. -x tells you the one with the largest magnitude will be negative.
-6 = -6×1 = -3×2 = ... (other factor pairs have a negative factor with a smaller magnitude)
The sums of these factor pairs are -5 and -1. We want the factor pair that has a sum of -1, the coefficient of x in the trinomial.
x² -x -6 = (x -3)(x +2)
The area of the circle would be 0.97
