Find the area of a sector with a central angle of 180° and a diameter of 5.6 cm. Round to the nearest tenth.

We calculate first for the area of the circle by the equation,

Area = πD²/4

Substituting,

Area = π (5.6 cm) ²/4 = 24.63 cm²

Then, we multiply this value by the ratio of the given angle to the angle of one whole revolution,

Area of sector = (24.63 cm²) (180/360) = 12.315 cm²

Therefore, the area of the sector is approximately 12.315 cm².