points A, B and C lie on a circle with center Q.

~ The area of sector AQB is twice the area of sector BQC.

~ The length of arc AB is 28 centimeters.

What is the length, in centimeters, of arc BC?

Respuesta :

Answer:

Length of arc BC is 14 centimeter.

Step-by-step explanation:

Point A, B and C lie on a circle with center Q.

The area of sector AQB is twice the area of sector BQC.

[tex]\text{Area of sector AQB}=2\text{Area of sector BQC}[/tex]

[tex]\text{Formula for area of sector:} =\frac{\theta}{360^{\circ}}\times \pi r^2[/tex]

Let sector AQB subtended angle [tex]\theta_1[/tex] at centre.

Let sector BQC subtended angle [tex]\theta_2[/tex] at centre.

[tex]\therefore \frac{\theta_1}{360^{\circ}}\times \pi r^2=2\times \frac{\theta_2}{360^{\circ}}\times \pi r^2[/tex]

[tex]\theta_1=2\theta_2[/tex]

[tex]\text{Formula for Length of arc:} =\frac{\theta}{360^{\circ}}\times 2\pi r[/tex]

Length of arc AB is 28 centimeters.

[tex]\text{Formula for Length of arc AB} =\frac{\theta_1}{360^{\circ}}\times 2\pi r[/tex]

[tex]\frac{\theta_1}{360^{\circ}}\times 2\pi r=28--------------(1)[/tex]

Length of arc BC is l centimeters.

[tex]\frac{\theta_2}{360^{\circ}}\times 2\pi r=l----------------(2)[/tex]

Divide equation 1 by equation 2 and we get

[tex]\dfrac{\theta_1}{\theta_2}=\dfrac{28}{l}[/tex]

[tex]\dfrac{2\theta_2}{\theta_2}=\dfrac{28}{l}[/tex]         [tex]\because \theta_1=2\theta_2[/tex]

[tex]l=\frac{28}{2}\Rightarrow 14\text{ centimeter}[/tex]

Thus, Length of arc BC is 14 centimeter.

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