The shaded figure below is composed of a trapezoid and a semicircle on a coordinate plane.
which of the following expressions represents the area of the shaded figure?
(figure and choice is in pic.)

The area of shaded region is:

                 2(12+π) square units.

We have the trapezium as:

Length of one base i.e. CD is:8 units.

Length pf other base i.e. AB is: 4 units.

Also height of trapezium is: 4 units.

Hence, Area of trapezium is: 1/2×4×(8+4)

                                              = 24 square units.

Similarly area of semicircle is: πr²/2

where r is the radius of the semicircle.

Clearly we have the diameter of semicircle as: AB=4 units.

Hence, Radius of semicircle is: 4/2=2 units.

Hence, Area of semicircle is: 2π square units.

Hence, area of shaded region is:

Area of semicircle+Area of Trapezium.

               =2π+24

                    =2 (12+π) square units.

answer: all of the odd numbers were opened

the first person was the one that was opening all of the lockers. since one is odd, this causes all of the odd number lockers to be opened in the end.