i have question again about the same link because i have national exam in one week i am trying to know way of solution of such recriational geometry problem see please below link of stated problem and it's solution.i have one question : is it correct?
Problem: find the area of the shaded region:
Solution: See how the region has been restructured. The right triangle that has been removed and the new one that has been added are both conguent by the property ASA (prove it!). Thus the two triangles have the same areas.
It is now easy to find the area of the shaded region: 9 square units.
is here everything correct? if not please can anybody tell me how to solve it?
Update: thanks guys everything is clear just i am curious what would be result if angle will not be right but anything else? could we find required area or it would be impossible?