Ok, here it is :
"All the triangles in the figure below are equilateral and the area of the shaded Triangle is 5cm squared."
http://4.bp.blogspot.com/_PnLYRqe0k9g/SnXtrcvf_nI/AAAAAAAAAKk/RRtqQiVRVqw/s320/Base+4+Triangle+units.png
In my diagram the shaded area is triangle 7.
"i) What is the area of the whole figure ?"
I was able to work this and the answer is 80cm squared, but I don't know the following :
"ii) Find the length of the side of the largest triangle in the figure (1 d.p.)
The largest triangle in the figure can be folded along the dotted lines to form a triangular pyramid.
iii) If the volume of this pyramid is 37cm cubed, determine the height of the pyramid ( correct to the nearest cm cubed )
iv) Explain why the value obtained in part iii is not the exact value of the height."