In a square pyramid, the perimeter of the base is 72 m. The surface area is 864 m squared.

Question

Find the slant height of the pyramid.

Answer 1

In square pyramid,

The slant height : l

The perimeter of the base :4s = 72m

                                                    s = 18m

The surface area : s² + 2sl = 864sq.m

                                  18² + 2(18)l = 864

                                   324 + 36l = 864

                                            36l = 864 - 324

                                             36l = 540

                                                  l = 15m

Therefore the slant height  = 15m.