Question

10.2.1BFind the measure of angle A for the triangle shown./1000сAThe value of angle A is

Answer 1

By definition, the sum of the interior angles of a triangle is 180 degrees.

In this case, you have the triangle ABC shown in the picture. Since you know the measure of two angles (angle B and angle C), you can set up the following equation:

`\begin{gathered} m\angle A+m\angle B+m\angle C=180\degree \\ m\angle A+100\degree+47\degree=180\degree \end{gathered}`

Finally, you need to solve for the angle A in order to find its measure. You get that this is:

`\begin{gathered} m\angle A+147\degree=180\degree \\ m\angle A=180\degree-147\degree \\ m\angle A=33\degree \end{gathered}`

The answer is:

`33\degree`