# What is a pentagonal pyramid

## Special pyramids optional subtasks 2003-2013 secondary school leaving certificate Document with 7 tasks

Source RS conclusion BW 2003

 The following are known of a regular nine-sided pyramid: M = 300 cm2 (Outer surface) a = 6.4 cm (Base edge) Calculate the volume of the pyramid. Solution: V = 473 cm3
Source RS degree BW 2005 A regular pentagon has the length of the side a = 3.6 cm.
If you lengthen all the pentagonal sides, the network of a regular pyramid is created.
Calculate the surface area and the volume of the pyramid.
 Solution: M = 49.9 cm2V = 36.8 cm3  Source RS conclusion BW 2007

 From a regular five-sided pyramid are given: M = 126 cm2 (Outer surface) HS.= 8.4 cm (Height of the side surface) Calculate the area of ​​the triangle AFS. a a a Solution: A.AFS= 33.8 cm2  From a massive regular five-sided pyramid are known: V = 329 cm3 (Volume of the pyramid) a = 7.0 cm Part of the pyramid is cut out (see sketch).Calculate the surface of the resulting body. a a a Solution: ONew= 314.6 cm2  