Hi,
so you have two triangles of the same side on two sides of the shape.
The shape is the same size split in half.
So 5cm is added twice
then you consider the other time so that’s twice again.
Then you do the same with 15
so it should be
15
5 5
4.6 4 15 4 4.6
5. 5
15
then you just solve for the area
