Why the value of π in geometry is 180° and how to find area of a trapezium

Pi in geometry means pi radians.it is an angle1 radian is the angle substended at the center of the circle if we take the arc length = radius of the circleSimplyAngle(in radians)=arc length/ radiusSo if arc length=2πrAngle(rad.)=2πr/r=2πTherefore a complete circle has 2π radians360°=2π radiansSo 180°=π radians************ To find the area of the trapeziumBreak it into a rectangle and a triangleAnd add the triangle on the defecient part of the trapezium so it eventually forms a rectangle and you can find the area easily