Posted by **lindsay** on Saturday, April 21, 2012 at 5:18pm.

given triangle ABC with AB=7cm, BC=8cm and AC=9cm calculate

1. the size of the largest angle

2. the area of the triangle

- trigonometry -
**Reiny**, Saturday, April 21, 2012 at 5:24pm
1.

the largest angle is opposite the largest side, so set your cosine equation up this way:

9^2 = 7^2 + 8^2 - 2(7)(8)cosŲ

2.

once you have that angles use the area formula

area = (1/2)(a)(b)sinŲ , where Ų is the contained angle.

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