in a traingle ABC three sides is given 6cm, 5cm and 5.6cm is given, what will be the length of a perpendicular drawn on the side BC with A as vertex

Answer 1

BC (b) times half the length of the perpendicular (h/2) equals the area.

Use Heron's formula for the area in terms of the lengths of the three sides:

http://mste.illinois.edu/dildine/heron/triarea.html

Set that equal to (1/2) b*h and solve for h.