ALEX Classroom Resource

Students:

• Demonstrate using a protractor to measure angles in different orientations to the nearest degree.
  Example: Given an angle, align the vertex of the angle with the correct point on the protractor, align one ray of the angle with the 0^o mark on the protractor, and read where the other ray is located on the protractor.
• Draw an angle of a given size using a variety of tools.
  Example: Draw a ray and use a protractor to construct a 108^o angle.
• Determine the angle measure when given an image of a protractor with angle rays intersecting the protractor scale.

Example: Given a protractor showing angle rays intersecting the protractor at 83 degrees and 123 degrees. What is the angle measure? Determine the angle measure is 40 degrees.

Students know:

• Measurable attributes of geometric shapes, specifically angle size.
• Units of measurement, specifically one-degree angle (degrees).
• An angle is measured by the number or iterations of one-degree angles that exactly cover the rotation of the angle.

Students are able to:

• Sketch angles given a specified measure.
• Use appropriate tools to find angle measure.

Students understand that:

• the rotation of an angle is measured by the number of one-degree angles that exactly cover the rotation of the angle.

Learning Objectives:
M.4.25.1: Define symmetry.
M.4.25.2: Model using a protractor to draw angles.
M.4.25.3: Measure the length of an object twice, using length units of different lengths for the two measurements; describe how the two measurements relate to the size of the unit chosen.
M.4.25.4: Measure the length of an object by selecting and using appropriate tools such as a ruler.
M.4.25.5: Measure length using standard and non-standard units of measurement.
M.4.25.6: Plot points on grids, graphs, and maps using coordinates.
M.4.25.7: Draw points, lines, line segments, and parallel and perpendicular lines, angles, and rays.
M.4.25.8: Identify lines of symmetry on one-dimensional figures.