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14 votes
14 votes
What is the area of this triangle?

Enter your answer as a decimal in the box. Round only your final answer to the nearest tenth.

What is the area of this triangle? Enter your answer as a decimal in the box. Round-example-1
User Damin
by
2.7k points

1 Answer

17 votes
17 votes

Answer:

38.6 in^2

Explanation:

Find the third side using law of cosines

11.1^2 + 7^2 - 2(11.1)(7)cos 84 = x^2

x = 12.49

semi perimeter = (11.1 + 7 + 12.49)/2 = 15.29

Heron's formula for triangle area with 3 side lengths given

sqrt( ( 15.29)(15.29-11.1)(15.29-7)(15.29-12.49) ) = 38.56 in^2

User Grzegorz Olszewski
by
2.5k points