This puzzle plays like a kriss kross in that once you have cracked the clues, you must fit the answers in the grid. Unlike a kriss kross, words of different letter lengths never intersect. Indeed, each set of words can almost be considered as an individual puzzle.
Starter letters help you place words in the grid but, unless you have solved all three clues in a set, you cannot be absolutely sure that you are placing words in the correct places.
If the spell-out in the shaded squares can be deduced, it will provide assistance with any unsolved clues.
Solve the clues and then fit the answers into the grid, the three nine-letter words in the outside triangle of the pyramid, the three six-letter words in the middle triangle, and the three three-letter words in the inner triangle.