What is the area under this graph? I am getting 2 different answers when using two different methods.

Question

I found the area of the triangle using the formula first and got 2.25 Then found the area of the trapezium (Area of the whole graph) and subtracted the unshaded region and got 2.25 again. The third time, I split the triangle into 3 parts and found the areas of the triangle consisting of 2 smaller triangles and a trapezium in between to get 2.5 How is this possible? I double checked and it is all correct.

Answer 1

The picture is wrong (or at least misleading). The label "$1$" on the speed axis should read "$0.75$".