Chapter 4.1, Problem 56HP

To determine

To explain:

Reason for triangle has more obtuse angle than acute angles.

Answer to Problem 56HP

Triangles are classified by their third angle; if third angle is obtuse then triangle is obtuse.

Explanation of Solution

Given information:

  $△DGF$ is obtuse.

Calculations:

Elaina all triangles have at least two acute angles so using Ines reasoning all triangles will be classified as acute.

Instead, triangles are classified by their third angle.

If the third angle is also acute then the triangle is acute.

If the third angle is obtuse, as the triangle shown, the triangle is classified as obtuse.