SOLUTION: The lengths of the sides of a triangle are 13cm, 37cm and 40cm. Find the length of the altitude to the longest side, in cm...

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Question 1125927: The lengths of the sides of a triangle are 13cm, 37cm and 40cm. Find the length of the altitude to the longest side, in cm...
Found 2 solutions by solver91311, ikleyn:
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!






and



So



Solve for and then calculate


John

My calculator said it, I believe it, that settles it


Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
.

The standard strategy for solving such problems is to calculate the area of the triangle using the Heron's formula;

then to divide the area by the half of the base.



The perimeter of the triangle is  13 + 37 + 40 = 90 cm;  hence, the semi-perimeter is  90/2 = 45 cm.



By the Heron's formula, area of the triangle is


    A = sqrt%2845%2A%2845-40%29%2A%2845-37%29%2A%2845-13%29%29 = sqrt%2845%2A5%2A8%2A32%29 = sqrt%289%2A5%2A5%2A2%5E3%2A2%5E5%29 = 3%2A5%2A2%5E4 = 3*5*16 = 240 cm^2.



Then the length of the altitude to the longest side  = 240%2F%28%2840%2F2%29%29 = 240%2F20 = 12 cm.

Solved.