You have two shapes - two identical isosceles triangles and a rectangle.
The area of a rectangle is base x height
The area of the two triangles is 2 x [(base x height*)/2]
12cm x 5cm = 60cm2
2 x (12cm x 4cm)/2) = 2 x (48cm2/2) = 2 x 24cm2 = 48cm2
60 + 48 = 108cm2
base or rect - 12cm
base of triangle - 12cm
height of rect - 5cm
height of triangle - 13cm - 5cm = 8cm /2 = 4cm for each triangle
