2. Mary Beth Briskey

3. *Objectives

4. Objectives The student will be able to achieve the following objectives by the end of this presentation: Identify and measure various types of angles Identify types of polygons based on shape characteristics Compute area, perimeter, and circumference for shapes Create geometric designs (tessellations) Web goals

5. Two rays that share the same endpoint form an angle. vertex side Angles The point where the rays intersect is called the vertex of the angle. The two rays are called the sides of the angle. What is an angle?

6. How do you measure an angle? The measure of this angle is… 120°

7. Type of Angles A RIGHT angle measures 90°. An obtuse angle measures from 90° to 180°. An ACUTE angle measures less than 90°. A STRAIGHT angle measures 180°

8. Type of Angles Complementary angles: angles whose measures add to 90° Supplementary angles: angles whose measures add to 180° 140 ° 40 ° 58 ° 32 °

9. What type of angle is greater than 90  and less than 180  ? Obtuse If two angles are complementary and one of them measures 40 , what is the measure of the second angle? 50  A ________ angle measures 90 . right What is the point where two rays intersect called? vertex

10. Shapes

11. Polygons Definition - a closed figure made by joining line segments, where each line segment intersects exactly two others. Parallelogram – a four-sided polygon with 2 pairs of parallel sides. NO

12. TRIANGLES Characteristics: 3-sided Polygon Sum of interior angles is 180° IsoscelesEquilateralRight 2 equal sides, 2 equal angles 3 equal sides, 3 equal angles One angle is 90°

13. Congruency Similarity Equal angles and equal sides Equal angles, proportionate sides Similar Symbol The corresponding congruent sides are marked with small straight line segments called hash marks. The corresponding congruent angles are marked with arcs.

14. Formulas

15. Area Measures the size of the region enclosed by the figure Rectangle:A = base x height Square:A = side ² Circle:A = П x radius ² Triangle:A = ½ x base x height b h s r h b

16. Perimeter The perimeter of a polygon is the sum of the lengths of all its sides. The perimeter of the following shapes is… 4 4 4 4 4 4 5 7 6 4 3 3 6 4 3 7 3 4+4+4+4+4+4 = 24 6+4+5+6+3+3+4=31 3+7+3+7=20

17. Circumference The distance around the outside of a circle. Formula: C = 2 x π x radius or C = π x diameter 5 C = 2 X 3.14 X 5 = 31.4

18. Geometric Designs

19. A tessellation is a repeated geometric design which covers an area without gaps or overlaps. How do you do it????

20. 4. Copy it Create your own Tessellation! 1. Draw a polygon 2. Reflect, rotate, translate 3. Color/fill

21. Learn More….. Geometry practice problems and lessons: 6th Grade Math Practice Math.com Homework Help Geometry Geometric designs/tessellations: Coolmath4kids.com - Tessellations