[Math] Given length of one side and its median and another median in a triangle. Find area of the triangle

geometrytriangles

Given the triangle $ABC$. If length of medians $AM=7.5$ and $BN=12$ and side $AC=6$, find the area of the triangle.

NOTE: Solution must not use any special formula or trigonometric functions.

My attempt : $NM$ is half of $AB$ in length, Triangles $ANO$ and $MOB$ have same amount of area.

Best Answer

First, use the lengths to solve for the semiperimeter ( which is half the perimeter ). Then set up Heron's formula (which would be area is equal to the square root of semiperimeter multiplied by semiperimeter minus side a multiplied by semiperimenter minus side b multiplied by semiperimenter minus side c. Here are the formulas you need:

S(semiperimeter)= 1/2 (a+b+c)

A (area)=√S (S-a)(S-b)(S-c)

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