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7-9. Tessellations. Course 3. Warm Up Identify each polygon. 1. polygon with 10 sides 2. polygon with 3 congruent sides 3. polygon with 4 congruent sides and no right angles. decagon. equilateral triangle. rhombus. 7-9. Tessellations. Course 3. Problem of the Day
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7-9 Tessellations Course 3 Warm Up Identify each polygon. 1. polygon with 10 sides 2. polygon with 3 congruent sides 3. polygon with 4 congruent sides and no right angles decagon equilateral triangle rhombus
7-9 Tessellations Course 3 Problem of the Day If each of the capital letters of the alphabet is rotated 180° around its center, which of them will look the same? H, I, N, O, S, X, Z
7-9 Tessellations Course 3 TB P. 368-371 Learn to create tessellations.
7-9 Tessellations Course 3 Insert Lesson Title Here Vocabulary tessellation regular tessellation
7-9 Tessellations Course 3 Fascinating designs can be made by repeating a figure or group of figures. These designs are often used in art and architecture. A repeating pattern of plane figures that completely covers a plane with no gaps or overlaps is a tessellation.
7-9 Tessellations Course 3 In a regular tessellation, a regular polygon is repeated to fill a plane. The angles at each vertex add to 360°,so exactly three regular tessellations exist.
7-9 Tessellations Course 3 Additional Example 1: Creating a Tessellation Create a tessellation with quadrilateral EFGH. There must be a copy of each angle of quadrilateral EFGH at every vertex.
7-9 Tessellations Course 3 Additional Example 2: Creating a Tessellation by Transforming a Polygon Use rotations to create a tessellation with the quadrilateral given below. Step 1: Find the midpoint of a side. Step 2: Make a new edge for half of the side. Step 3: Rotate the new edge around the midpoint to form the edge of the other half of the side. Step 4: Repeat with the other sides.
7-9 Tessellations Course 3 Additional Example 2 Continued Step 5: Use the figure to make a tessellation.
7-9 Tessellations Course 3 Insert Lesson Title Here Lesson Quiz 1. Explain why a regular tessellation with regular octagons is impossible. Each angle measure in a regular octagon is 135° and 135° is not a factor of 360° 2. Can a semiregular tessellation be formed using a regular 12-sided polygon and a regular hexagon? Explain. No; a regular 12-sided polygon has angles that measure 150° and a regular hexagon has angles that measure 120°. No combinations of 120° and 150° add to 360°