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Message: <blockquote data-quote="imhotep" data-source="post: 30012645" data-attributes="member: 562115">The main thing is the effort...which is appreciated. Thinking is brain food. <img src="/styles/default/xenforo/smilies/default/yes.gif"  class="smilie" loading="lazy" alt=":yes:" title="Yes    :yes:" data-shortname=":yes:" />Alternate way which I mentioned as a hint somewhere in here.Tip: It's  a Tetrahedron.... We know the volume is 1/3 x base x height. The area of the shaded base can be easily calculated, because the areas of the three traingular sides are easy. Now think a bit of another way to get at the volume of the pyramid. Then you have the answer.Solution: -The small triangle area is obviously 1/2 * 6 * 6 = 18 sq cmEach of the larger triangles 1/2* 6 * 12 = 36 sq cmThus the area of the shaded triangle = 144 - 2 * 36 - 18 = 54 sq cmThis gives us the area of the tetrahedron = 1/3 * base * height = 1/3 * 54 * h = 18h cu cm  (consider the shaded area is the base as shown in the diagram)Now, visualize the pyramid in another aspect.  The upper vertex has three folds, each containing three 90 degree angled surfaces making contact.If you take the smaller right angled surface of 18 sq cm as the base, you immediately realise that there is the 12 cm joining fold is perpendicular to this (as they all are 90 degrees)This straight away gives us the volume of the pyramid from this perspective, 1/3 * 18 * 12 = 72 cu cmThus 18h = 72 or h = 4 cm.......  <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite22" alt="(y)" title="Thumbs up    (y)" loading="lazy" data-shortname="(y)" />PS: Thanks for all those who tried or bumped the problem... Too many to mention individually. [USER=585634]@icewiz[/USER] came up with the first correct answer.</blockquote>

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