geometry
posted by rishabh .
The sies of a triangle are 9cm, 12 cm and 15cm. Find the lenght of the perpendicular drawn to the side which is 15 cm.

Since the sides are in a 3:4:5 ratio, it is a right triangle. The right angle is between the sides with lengths 9 and 12.
The smallest angle is
A = sin^1(3/5) = 36.87 degrees.
The perpendicular to the hypotenuse is
12 sin A = 12*sin36.87 = 12*0.6 = 7.2 cm