Answer:
79cm
Explanation:
I took the liberty of getting the complete question suce the one provided isn't and here it goes:
a trianglular pyramid has a base with an area of 7 square centimeters
and layeral faces with bases of 4 centimeters and height of 12
centimeters. what is the surface area of the pyramid
--- All we need to do here is to add up the areas of the base and the lateral faces.
Since we are dealing with a triangular pyramid there are 3 lateral faces.
The area of the base is given as 7 square cm
Each face is a triangle with base = 4 cm and height = 12 cm so
each face has an area of
A = (1/2) × base × height = (1/2) × 4 × 12 = 24 square cm
There are 3 lateral faces so the total surface area is
3x + 7 = 3 × 24 + 7 = 79 cm²