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A triangle has sides of length 3,4 and 6.

Prove that the area of the triangle is exactly 4554


Use the cosine rule to get the value of cos⁡θ. Don't round it - leave it as an exact value and then use

sin2⁡θ+cos2⁡θ=1

to find the exact value of sin⁡θ.


Now you know sin⁡θ you can use the area formula.