Let BC=CD=12cm, and the length of arc BD=15cm. Find the area, in square centimeters, of sector BCD.

Answer:
option b : 90 sq. cm
Step-by-step explanation:
1) Area of circle with radius = 12cm
Area = π r^2
= 3.14 * (12) (12)
= 3.14 * 144
= approx 452.4
2) Circumference of circle with radius = 12cm
Circumference = 2πr
= 2 * 3.14 * 12
= approx 75 .4
3) Arc length = 15cm ......(given)
[tex] \frac{area \: of \: sector}{total \: area} = \frac{arc \: length}{circumference} [/tex]
[tex] \frac{area \: of \: sector}{452.4} = \frac{15}{75.4} [/tex]
[tex]area \: of \: sector \: = \frac{15 \times 452.4}{75.4} [/tex]
[tex] = \frac{6786}{75.4} [/tex]
[tex] = 90 {cm}^{2} [/tex]