



 
Hi Lisa, In my triangle ADC the lengths of AD and CA are each equal to 8.4 cm. The area of the triangle ADC is
where b is the length of the base DC and h is the height, AC. Triangle ABC is a right triangle and hence by Pythagoras' Theorem
Substitute this value for b/2 into the expression for the area to get
At this point I would square each side to eliminate the square root. This gives a quartic in h but if you substitute x = h^{2} then you have a quadratic in x which you can solve. Finally h is the square root of x but remember that h must be positive. Penny  


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