Write two mixed numbers between 3 and 4 that have a product between 9 and 12.

A mixed number has a part that is whole and a part that is a friction.
For example:
3 1/2 and 3 2/3
3 1/2  * 3 1/4 = 7/2 * 13/4 = 91/8 = 11 3/8
9 < 11 3/8 < 12 

We know that 
3 × 3 = 9
And 3 × 4 = 12
Therefore, as long as both the numbers are greater than 3 and less than 7/2, the product will remain between 9 and 12
An example is:
(13/4.) × (33/10)
= 3.25 × 3.3
= 429/40 = 10.725

The lateral side of a triangular pyramid is a triangle. in order to increase the lateral surface area, the slant height and the height should be altered

It creates dogx^2 and then flip your answer and multiply by 2