What is the area of a sector with a central angle of 10pi/7 radians and a radius of 18.4 m? enter your answer as a decimal.

Will give brainliest sum of arithmetic series (sigma notation) find the numerical answer to the summation given below. (image shown below)

Answers; a) 135 degree’s b) 30 degree’s c) 180 or 0 degree’s d) 90 degree’s

How do i do this? i don’t understand