The perimeter of a triangular field is 240dm. If two sides are 78dm and 50 dm, find the length of the perpendicular on the side of length 50dm from the opposite

Question

Plz.. Solve this

Answer 1

the key here is to use two different ways to calculate the area. the first method is to use the 3 sides since they are all known to calculate the area. the second method is to use the 1/2 bh formula which in this case will have the b and area and missing the h and that is what is required.

 

perimeter = 240 = 78+50+Y

Y = 240 - 128 = 112

 

s = 1/2 the perimeter = 120

Area = sqrt [s (s-a)(s-b)(s-c)] = sqrt (120 x 70 x 42 x 8) = 1680

 

Area = 1680 = 1/2 x 50 x h

h = 67.2