For this case we have that by definition, the area of a circular sector is given by:
[tex]A = \frac {a * r ^ 2} {2}[/tex]
Where:
r: It's the radio
a: It is the angle of the sector
We have to:
a = 90 degrees
[tex]90\ degrees = \frac {\pi} {2}[/tex]
Then, replacing:
[tex]A = \frac {\frac {\pi} {2} * 15 ^ 2} {2} = \frac {225 \pi} {4}[/tex]
Answer:
Option A
