Skowhegan Area High School
 Topics Introduction Using Slope and Distance to determine the midpoint and type of polygon (parallel and perpendicular) Geometric and rigid transformations Size Transformations Matrices GEOEXPLOR Multiplication and Addition Algorithms
 Math 2 Unit 2 SIZE TRANSFORMATIONS This lesson will help you see: 1) The effects of size transformations on length, slope, and area for various shapes. 2) The concepts associated with size transformations and similarity for plane shapes. What is a Size Transformation??? A size transformation is actually changing the size of an object by multiplying or dividing the coordinates by a specific factor. Example: (x,y)-->(2x,2y) (5,5)-->(2x5, 2x5) or (10,10) Length of a side= 5 Area= 25 Length of a side= 10 Area= 100 L1= Small Square L2= Large Square Here, your second point (2x,2y) is two times as large as your first point (x,y). Also, the area of the shape above increases by a multiple of 4 (the size factor increased by 2 on each side). If the length was multiplied by a factor of 3, then the area would increase by a factor of 3 on each side or 9 because you multiply them. The slope remains the same in the size transformation because the shape remains the same. Only the size and area change. ANOTHER EXAMPLE: In the example to the left, you can see that when transforming an image by a factor of 2, you simply multiply all of the points by that factor. Here the shape doubles in size and quadruples in area. Again, the slope remains constant in both images.