Question

Find m< A
Round to the nearest degree

Answer 1

a bit more than 48°

Explanation:

We use the law of cosines for this.

The theorem is an extension of pythagoras' theorem, working for all triangles. In our case

`\overline{BC}^2=\overline{AB}^2+\overline{AC}^2-2\overline{AB}\cdot\overline{AC}cos \hat A`

Let's replace all the values we have and find whatever is left.

`10^2=11^2+13^2-2(11)(13)cos \hat A\\-286cos\hat A = -190\\cos \hat A\approx 0.6643 \rightarrow \hat A \approx 48\°`