Given, a net for a triangular pyramid.
The triangular pyramid consists of 4 equilateral triangle
As shown, the base of one triangle = 6 cm
The height of one triangle = 5.2 cm
The area of one triangle =
![(1)/(2)\cdot6\cdot5.2=15.6\operatorname{cm}^2]()
So, the surface area = 4 times the area of one triangle
![=4\cdot15.6=62.4\operatorname{cm}^2]()
so, the answer will be Surface area = 62.4 square cm.