Given:
Length of a side of base of a square base pyramid = 6 cm
Height of each triangular surface = 4 cm.
To find:
The total surface area of the square based pyramid.
Solution:
Area of a square with side length a is

Area of square with side length 6 cm is


So, area of square with side length 6 cm is 36 cm².
Area of triangle is

Area of each triangular surface is


Total area of 4 triangular surfaces is


So, area of all triangular surfaces is 48 cm².
Now, total area of pyramid is the sum of base area and area of all triangular sides.


Therefore, the area of given square pyramid is 84 cm².