Question

In triangle ABC the measure of angle A = 112, b = 8, and c = 14. Identify a rounded to the nearest tenth.

Answer 1

a =18.5

The formula:

`a^2=c^2+b^2-2cb\cos (A)`

a = ?

A = 112

b = 8

c = 14

`\begin{gathered} a^2=8^2+14^2-2\cdot8\cdot14^2\cos (112) \\ a^2=64+196-2\cdot8\cdot14\cdot(-0.3746) \\ a^2=64+196+83.91188 \\ a^2=343.9118 \\ a=\sqrt[]{343.9118} \\ a=18.544 \\ a\cong18.5 \end{gathered}`