Student, this scenario is for the recognition of some special shapes that an angle can present. Explore these shapes by moving the points O, A and B. Then, select the "SHOW PHOTOS" and explore the different angle’s shapes according to the situations illustrated in the photos.

Student, you may have noticed three types of shapes. One of these shapes gives the idea of a sharp tip, and an angle with this form is called acute angle. Another angle’s shape represents the opposite idea of acute angle, when something seems coarse, with no penetration power. An angle like this is called an obtuse angle. The last type of shape angle passes the idea of something that does not even leans to one side or the other, to be just, righteous. In this case, the angle is called a right angle.