Geometry Georgia Performance Standards Jan Munroe Sawnee Elementary School Forsyth County Schools

Angles An angle is formed by 2 rays or 2 line segments that share the same endpoint. Angle formed by two rays Angle formed by 2 segments The endpoints where the rays or segments meet is called the vertex of the angle. The rays or segments are called the sides of the angle.

Classifying Angles A right angle measures 90 degrees. An accute angle measures between 0 and 90 degrees. An obtuse angle measures between 90 and 180 degrees. A straight angle measures 180 degrees A reflex angle measures between 180 and 360 degrees. Angles may be classified according to size. Use the protractor tool to measure the angles below.

A right angle measures 90 degrees. An accute angle measures between 0 and 90 degrees. An obtuse angle measures between 90 and 180 degrees. A straight angle measures 180 degrees A reflex angle measures between 180 and 360 degrees. Now let's check for understanding. Use the spotlight tool to identify the angles below as the names are called. Then drag away the yellow to reveal the answers!

Use the spotlight tool to locate the right, acute, obtuse, reflex and straight angles in the illustation below. A B C D E F G

Parallel and Perpendicular Lines Parallel lines are lines on a flat surface that never meet. They are always the same distance apart. Perpendicular lines are lines that intersect or cross and form right angles.

Triangles are the simplest type of polygons. The prefix tri means three. Triangles have 3 vertices, 3 sides,and 3 angles. Equilateral Triangle Isosceles Triangle Scalene Triangle Right Triangle All sides and angles are equal. Has one right (90 degree angle). Has two equal sides and two equal angles. Has no equal sides and no equal angles.

Isosceles Triangles Right Triangles Scalene Triangles Equilateral Triangles Drag the triangles at the bottom of this page to the boxes in which they belong!

A quadrangle is a polygon that has 4 sides. Another name for quadrangle is quadrilateral. The prefix "quad" means four. All quadrangles have 4 sides, 4 vertices and 4 angles. Quadrangles with 2 pairs of parallel sides. Square Has 4 equal sides and 4 equal angles. Rectangle Opposite sides are equal. Parallelogram Trapezoid Rhombus All sides may have different lengths and angles may be different. Opposite corners of a square are pulled in opposite directions.

TrapezoidParallelogram Rectangle Square

Check for Understanding ____ 1. Which one of the following figures is a trapezoid? ____ 2. Which one of the following figures is a right angle? ____ 3. Which one of the following figures is a parallelogram? A. B. C. A.B. C. B.A.

Check for Understanding ____ 4. Which one of the following figures is an equilateral triangle? ____ 5. Which one of the following figures is an example of parallel lines ? ____ 6. Which one of the following figures is an acute angle? A. B.C. A.B. C. B.A.

Use the voter button to select the correct answer. 1. A right angle measures A. 180 degrees B. between 0 and 90 degrees C. 90 degrees

2. A reflex angle measures A. between 180 and 360 degrees B. between 90 and 180 degrees C. 180 degrees

3. A straight angle measures A. 90 degrees B. between 90 and 180 degrees C. 180 degrees

4. Acute angles measure A. between 180 and 360 degrees B. between 0 and 90 degrees C. between 90 and 180 degrees

Use the voter button to select the correct answer. 6. Lines or line segments that never meet and are always the same distance apart are called A. intersecting lines B. parallel lines C. perpendicular lines

7. Lines or line segments that cross and form right angles are called A. intersecting lines B. parallel lines C. perpendicular lines

8. Lines or line segments that cross each other are called A. intersecting lines B. parallel lines C. perpendicular lines

10. A triangle with one right angle is called A. a scalene triangle B. an equilaterial triangle C. a right triangle

11. A triangle that has no equal sides is called A. a scalene triangle B. an equilateral triangle C. a right triangle

Use the voter button to select the correct answer. 12. A quadrilateral that has two pairs of parallel sides is called A. a trapezoid B. a kite C. a parallelogram

13. A quadrangle with 1 pair of parallel sides and may have different lengths for all sides is called A. a trapezoid B. a kite C. a parallelogram

14. Quadrangles that are parallelograms are A. trapezoids and kites B. rectangles, rhombuses and squares C. cubes and trapezoids

Credits Bell, M. (et.al.). Everyday Mathematics. The University of Chicago School Mathematics Project. Everyday Learning: Chicago, Illinois, 2002.