Find the area of a sector with a central angle of 100 and a diameter of 5.1 cm. Round to the nearest tenth

Ok so basically what you do is the whole circle is 360 degrees 100/360 of it is shaded find 100/360 of the area of the whole thing 100/360=10/36 area=pir^2 d/2=r 5.1/2=r=2.55 aprox pi=3.141592 area=3.141592 * (2.55) ^2 area=20.42820198 not multiply by 10/36 204.2820198/36 5.67450055 round 5.7 answer is 5.7cm^2

I used 3.14 for pi and pi/180 to convert degrees to radians.