Question

3) A B C D E is a pentagon. How many triungle will you get if
you join the point A to the remaining points​

Answer 1

Answer:

Draw the altitude from point C, and call H its intersection with the side AB. Point H divides the length of the hypotenuse c into parts d and e. The new triangle ACH is similar to triangle ABC, because they both have a right angle (by definition of the altitude), and they share the angle at A, meaning that the third angle will be the same in both triangles as well, marked as θ in the figure.