Geometry and Solid Figures: Triangles

In any triangle, the sum of all angles is 180 degrees.
-  Area of a triangle


Examples:


Example 1.

What is the area of this triangles?
Solution: Use the area formula:


and , Then:



Example 2.  What is the area of this triangles?

Solution: Use the area formula:


and ;

Example 3. 

What is the missing angle in this triangle?
Solution:

In any triangle, the sum of all angles is 180 degrees. Let be the missing angle.
Then:

The missing angle is 45 degrees.