1. Geometry Overview

2. Angles AngleSizeExample Right90˚ Straight180˚ Acute<90˚ Obtuse>90˚

3. More on angles Vertical Angles –Opposite angles are equal –Angle A = Angle C –Angle B = Angle D A C B D

4. Triangles Name Characteristics EquilateralAll sides equal Isosceles2 sides equal ScaleneNo sides equal Name Characteristics Right1 right angle Obtuse1 obtuse angle AcuteAll angles are acute

5. Similar and Congruent Congruent –Same shape –Same size Similar –Same shape –Different Size

6. Similar Figures If figures are similar, they are in proportion to one another. You can check this by writing a proportion and seeing if it is equal 4ft 10ft 2ft 8ft 4 = 2Since 4x8  2x20 10 8 These figures are not similar

7. Dimensional Objects 1 Dimensional - Units –X axis only –Line 2 Dimensional – Units 2 or sq. units –X-Y Axis –Square, circle, triangle, etc. 3 Dimensional – Units 3 or cu. units –X-Y-Z Axis –Cube, prism, cone, sphere

8. 2-D Shapes PictureNamePerimeter (Units) Area (Units 2 ) Characteristics SquareAdd up all the sides s2s2 All sides equal All angles 90˚ RectangleAdd up all the sides Length x WidthOpp. sides equal All angles 90˚ TriangleAdd up all the sides Base x Height 2 3 sides. Angles add to 180All sides equal 180˚ ParallelogramAdd up all the sides Base x Height Opposite sides equal and parallel Opposite angles equal TrapezoidAdd up all the sides Base1+Base2 x Height 2 Two sides parallel, two side not parallel Circle  D or 2  r r2r2 All points on a plane equidistant from center

9. 3-D Shapes ShapeNameVolume (Units 3 ) Surface Area (Units 2 ) Rectangular Prism Length x Width x Height 2LW + 2WH + 2LH Cylinder Area of base(  r 2 ) x Height  D x Height +  r 2