Dear Student, Welcome to Looking at an Angle! In this unit, you will learn about vision lines and blind areas. Have you ever been on one of the top floors of a tall office or apartment building? When you looked out the window, were you able to see the sidewalk directly below the building? If you could see the sidewalk, it was in your field of vision if you could not see the sidewalk, it was in a blind spot. The relationship between vision lines and rays of light and the relationship between blind spots and shadows are some of the topics that you will explore in this unit. Have you ever noticed how the length of a shadow varies according to the time of day? As part of an activity, you will measure the length of the shadow of a stick and the corresponding angle of the sun at different times of the day. You will then determine how the angle of the sun affects the length of a shadow. Besides looking at the angle of the sun, you will also study the angle that a ladder makes with the floor when it is leaning against a wall and the angle that a descending hang glider makes with the ground. You will learn two different ways to identify the steepness of an object: the angle the object makes with the ground and the tangent of that angle. We hope you enjoy discovering the many ways of "looking at an angle."