



 
Hi Brian, Suppose the base has length b, each of the other two sides has length a, the perimeter is p and the height is h. Let Q be the midpoint of the base and draw a line from Q to the apex of the triangle P.
By the symmetry angle PQR is a right angle and thus the Theorem of Pythagoras applies so that
You also know that
Use these equations to find an expression for b in terms of p and h. Penny  


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