Provide your best answer for the following math problem. Give ONLY the answer, no other words or explanation.
For example:

Answer: <most likely answer, as short as possible; not a complete sentence, just the answer!>.

The problem is: calculate the area of a triangle , if the sides are 30 cm , 21 cm and 10 cm , what is its area ?
105 cm 2
132.933333333 cm² (rounded to 7 decimal places)