Cos(x) = BC/AB = 10.5/20 = 0.525 ⇒ x = 58.3°
90/15-7/15=83/15 the correct answer to this equation.
Answer:

Step-by-step explanation:
The <u>total area</u> of the circle is given by:

where
is a constant 
and
is the radius: 
Thus the total area of this circle is:

We want only the area of the arc that measures 50°. For this we must remember that the arc of the total circle is 360°.
Thus, we want 50° out of the 360° degrees in the circle. For this, we divide the total area by 360 and then we multiply by 50:

the area of the sector to the nearest tenth is 
Let x represent the number:
2/3(x)+15=9
2/3(x)= -6
x= -6/(2/3)
x= -6*(3/2)
x= -9