projection screen in a classroom setting

projection screen in a classroom setting. A projector is mounted on the wall, casting an image of a structural engineering problem onto the screen. The problem statement describes a rectangular section beam with dimensions 200mm x 600mm, reinforced with 4Φ20 + 2Φ22 longitudinal tensile reinforcement, and made of concrete grade C35. The design bending moment is 300kN.m, and the question is whether the beam is safe. The screen also displays a structural diagram showing the beam's dimensions and reinforcement layout, noting a height of 600mm and a width of 200mm. The logo of Chongqing Vocational Institute of Engineering Technology is visible on the screen. Two people, one with curly hair and another with a black knit hat, are partially visible in the frame, presumably observing the projection. The location is Jiangjin, China.