C58 Agglomerated quicksand(part ii)

"The trapezoid area formula is the upper bottom plus the bottom multiplied by the height divided by the second. Do you understand? "Because there's a rectangle after the next match, do you know …"

"Two is because of the vertical line. Look, isn't it two triangles …"

"Motherf * cker, my god …"

After speaking for a while, I realized that Zhang Kefan's foundation was truly not that good