Posted by Lloini on .
Find the surface area of a triangular pyramid with b =4 cm, h= 8.2 cm and s = 7 cm. PLEASE. How ?

GEOMETRY (SA oftriangular pyramid) 
MathMate,
Lateral surface area
=perimeter of base * apothem /2
=3b*s/2
(for a regular pyramid with a triangular base)
Area of triangular base with side b
=(√3)*b/2*(b/2)
=(√3)b²/4 
GEOMETRY (SA oftriangular pyramid) 
Anonymous,
What is apothem ?

GEOMETRY (SA oftriangular pyramid) 
Anonymous,
why did you not include the height ?