Brain-Teaser 222: British triangles

From The Sunday Times, 25th July 1965 [link]

British Triangles, naturally, stand on horizontal bases with their points upwards. All their sides, never more than a  sensible 60 inches, and their heights measure an exact number of inches. No B.T. is isosceles or right angled.

You can often put more than one B.T. on a common base. On a base of 28 inches 8 B.T.s are erected.

What are their heights?

This puzzle was included in the book Sunday Times Brain Teasers (1974, edited by Ronald Postill).