The area of the circle is calculated through the equation,
A = πr²
where A is the area and r is the radius. An alternate equation can be used,
A = πD²/4
where D is the diameter.
Substituting the known value to the equation,
A = π(9.1 cm)² / 4
A = 65.03 cm²
The area of the sector, As, is calculated by multiplying the area of the circle by the ratio of the angle to the whole revolution.
As = (65.03 cm²) x (170°/360°)
As = 30.71 cm²
The answer to this question is therefore letter B.