The area of a sector of a circle with a radius of 4 centimeters is 2.512 square centimeters. the estimated value of π is 3.14. the measure of the angle defining the sector is °.'

Area = (theta/360)* pi * r^2 
where theta is the angle of  the sector 
subs by your givens in the above equation 
2.512 = (theta/360) * pi * (4)^2 
theta = (2.512 * 360) /(pi*(4)^2)
theta = 18 degree 

Answercounterclockwise rotation about the origin by 180 degrees followed by reflection about the y-axisexplanationthe given figure has verticesrecall that for counterclockwise rotation about the origin, when we rotate figure pqrs counterclockwise through an angle of 180° about the origin, the coordinates will becomenext, we reflect in the y-axis by negating the x-coordinates of the resulting figure to obtain,therefore the correct answer is c