Fifth grade plane geometry pulling problems

2022-05-20 0 By

Who would have thought that the sixth graders would be stumped by a line of fifth grade plane geometry!Let’s take a look at this!As shown in the figure, in rectangle ABCD, AD = 8cm, CD = 6cm, AE = 4cm, DF and CB extension lines intersect at point F, and the area of the shaded part is calculated.At first glance, this seems easy, because the shaded part is a right triangle.And knowing that a right-angled side is equal to 2 centimeters a day, many children like to find another right-angled side!In that case, you are dead wrong!In fact, we should connect A.F, and then through the base height model, we can know the area relationship between the shaded part and the triangle AEF, we can calculate the area of the shaded part through the triangle AEF!