question_answer

A right pyramid stands on a rectangular base whose sides are 24 cm and 18 cm and each of the slant edges is 17 cm. The height of he pyramid is

A)  8 cm                       

B)         10cm             

C)  12cm                   

D)         15cm            

Correct Answer: A

Solution :

\[P{{R}^{2}}=P{{C}^{2}}-C{{R}^{2}}\] \[={{17}^{2}}-{{9}^{2}}\] \[=208\]                                 \[Heigh{{t}^{2}}=P{{Q}^{2}}\]                                 \[=P{{R}^{2}}-Q{{R}^{2}}\]                                 \[=208-144=64\]                 \[\therefore \]  Height \[=8\,cm\]