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## August 25 , 2014

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**August 25, 2014**-Take out a pencil and prepare for your first warm-up Essential Question: What are the building blocks of geometry?**Warm-Up**Looking at the pictures below, write a short description of what an “Ork” is. Now choose: Which one of the four would be considered an Ork? Orks all have curved bodies. They also have at least one tail. They all have the black dot inside.**Writing Assignment**• Write a paragraph to answer the following questions: • What makes a good definition? • Why do we need to know our definitions? • What would be an example of a bad definition? • Why are definitions important in a Geometry class?**Definitions**• Point: It has location and nothing else. No size. No height. No depth. No friends. The basic unit of geometry. Capital Letters are used. • Line:A straight, unbroken set of points that goes on forever. It has infinite length but no thickness. Point A h Look at the notation, above the letters are symbols that look like lines We can also use one letter. This one is lowercase and in script Line h**Definitions**M A • Plane : a surface that has length and width but no thickness. It is a flat surface that extends forever. • Line Segment: A line that has two endpoints • Ray: A line that contains only ONE endpoint. B C plane M Plane ABC See how the notation uses a line segment without arrows on the ends. Once again, notice the notation uses a symbol that looks like a ray.**Definitions**• What are some words that have the prefix co-? • What does that prefix mean? • Collinear: • On the same line • Coplanar: • On the same plane M A B C**Last Definition!**• Angle: two rays that share a common endpoint, provided the two rays do not lie on the same line. That common endpoint is known as the vertex. D E F Note: If there was another line coming out of the vertex, you cannot name the angle by the vertex since it represents too many angles.**Physical Models in Real Life**Point Line Plane**Physical Models in Real Life**Angle Ray**Exit Slip**Write your answers on a half sheet of paper. • If two planes intersect, what does the intersection look like? • If two lines intersect, what does the intersection look like? • If a line an a plane intersect, what does the intersection look like? • Name another real-life example of a plane and an angle. • Does plane ADQP exist in the following picture?