1. Subject: Geometry Unit :Basic Elements of Geometry Lesson: What are the classifications of angles and where can angles be found in the real world? Standards Addressed: GMG1- Use geometric shapes, their measures, and their properties to describe objects. GCO1- Know precise definitions of angle, perpendicular line, parallel line, line segment based on the undefined notion of point, line, and plane.

2. Angle Measurement Find the following angle measures: m<AOG m<AOG m<IOH m<IOH m<DOE m<DOE m<COG m<COG M<AOH M<AOH

4. 4 Classification of Angles Classification of Angles An acute angle is an angle that measures less than 90 degrees. An acute angle is an angle that measures less than 90 degrees. A right angle is an angle that measures exactly 90 degrees. A right angle is an angle that measures exactly 90 degrees. An obtuse angle is an angle that measures more than 90 degrees. An obtuse angle is an angle that measures more than 90 degrees. acute rightobtuse

5. 5 Classification of Angles Classification of Angles A straight angle is an angle that measures 180 degrees. (It is the same as a line.) A straight angle is an angle that measures 180 degrees. (It is the same as a line.) When drawing a right angle we often mark its opening as in the picture below. When drawing a right angle we often mark its opening as in the picture below. straight angle right angle

6. Geometry in Architecture

7. What is the relationship between Architecture and Geometry?

8. Architects provide services related to the design and construction of buildings and the space around them. City planners help design cities and make such determinations as the height of buildings and the width of streets. Architects and City Planners must be able to think in terms of spatial relationships and visualize the effects of their plans and designs. Angles, lines and other geometric shapes are important in the design of every structure or neighborhood.

14. Task: Submit a picture of an angular or triangular shaped object. Describe the object, how it is used and why the object’s shape is useful or beneficial. Picture and description may be emailed.

15. Student Work

17. An Ames room is a distorted room that is used to create an optical illusion. An Ames room appears to be an ordinary square-shaped room, with a back wall and two side walls parallel to each other and perpendicular to the horizontally level floor and ceiling. However, the true shape of the room is trapezoidal, the walls are slanted and the ceiling and floor are at an incline. As a result of the optical illusion, a person standing in one corner appears to the observer to be a giant, while a person standing in the other corner appears to be a dwarf. The illusion is convincing enough that a person walking back and forth from the left corner to the right corner appears to grow or shrink..

19. Gable: The triangular area of a wall between the slopes of a double-shaped roof. Gable roofs are one of the worst types of roofs to have in hurricane regions. They easily peel off in hurricane winds, and the gable end "catches wind like a sail.“ Benefit of triangle roof is snow and rain do not remain on top.

21. As the angle of the slope increases so does the steepness of the slope. The skier also travels at faster speeds on greater slopes.

22. Safe Angle