(Originais Teachy 2023) - Question Easy of Mathematics

In the Geometry class, teacher João decided to teach about right and non-right angles using everyday shapes. He showed the students a figure of a rectangular window and explained that the vertical and horizontal lines forming the window are perpendicular, which means they meet to form four right angles. Then, he brought a photograph of a park with an oval-shaped lake and asked the students how many right angles a shape like that has, leading them to think about the characteristics of shapes and the relationship between angles. Considering the learning about right and non-right angles and the observation of the presented geometric shapes, how many right angles does an oval-shaped lake have? Also, describe how you reached this conclusion.