How to find the area of a trapezoid in seconds.

to find the area of a trapezoid, we are likely to find the lengths of sides. however that way is complicated. in this geometry problems, this triangle is an isosceles right triangle. so we can use the properties of an isosceles right triangle. if so, this problem can be solved very easily. this video shows how to find the area of a trapezoid in seconds. (made by vrew)
#areaofatrapezoid #isoscelestriangle #geometryproblems

[@stephenlesliebrown5959]

Since the slope of the top of the trapezoid is not definite we are free to slide the dimension 6 bottom all the way to the right causing b to become zero and the yellow figure becomes a right triangle. The area is (1/2)(base)(height) = (1/2)(6)(6) = 18.

[@math_travel]

you are right because a+b is always constant. I think it would be better to show in advance that we can transform this trapezoid as you explained. thanks for a good idea!

[@stephenlesliebrown5959]

​​@@math_travel I should have added "Since the drawing is not to scale" 😆

[@math_travel]

@@stephenlesliebrown5959 I was wondering if I have to prove that the area does not change in spite of transforming the trapezoid given. now I am wondering if the mention you add is enough for proving that.

[@stephenlesliebrown5959]

@@math_travel I believe it is enough to realize what you said, that a+b is constant. 🙂