Maryland College and Career-Ready Standards
MD.MA.4.MD. Measurement and Data (MD)
4.MD.C. Geometric measurement: understand concepts of angle and measure angles.
4.MD.C.5. Additional Standard: Recognize angles as geometric shapes that are formed wherever two rays share a common endpoint, and understand concepts of angle measurement.
4.MD.C.5.1. See 4.MD.C.5a-4.MD.C.5b for the skills and knowledge that are needed for this Standard.
4.MD.C.5a. Additional Standard: Recognize angles as geometric shapes that are formed wherever two rays share a common endpoint, and understand concepts of angle measurement – An angle is measured with reference to a circle with its center at the common endpoint of the rays, by considering the fraction of the circular arc between the points where the two rays intersect the circle. An angle that turns through 1/360 of the circle is called a “one-degree angle,” and can be used to measure angles.
4.MD.C.5a.1. Knowledge of partitioning circles into equal shares (2.G.A.3).
4.MD.C.5a.2. Ability to relate understanding of equal shares of a circle to angles.
4.MD.C.5a.3. Ability to use visual aids and/or technology to apply the understanding of how a circle is divided into 360 degrees (e.g., circle protractor or geometry software).
4.MD.C.5a.4. Introduce the unit of measurement of a circle (degrees). Students need to understand that a whole circle is 360 degrees by taking a circle and dividing it into 1/2, 1/4, 1/8, etc. so that 1/2 is 360 divided by 4, etc.
4.MD.C.5b. Additional Standard: Recognize angles as geometric shapes that are formed wherever two rays share a common endpoint, and understand concepts of angle measurement – An angle that turns through n one-degree angles is said to have an angle measure of n degrees.
4.MD.C.5b.1. Knowledge that each angle measure is a result of how much of the circle is covered (e.g., shading in 50 parts of the 360 would equal a 50 degree angle).
4.MD.C.6. Additional Standard: Measure angles in whole-number degrees using a protractor. Sketch angles of specified measure.
4.MD.C.6.1. See the skills and knowledge that are stated in the Standard.
MD.MA.4.G. Geometry (G)
4.G.A. Draw and identify lines and angles, and classify shapes by properties of their lines and angles.
4.G.A.1. Additional Standard: Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures.
4.G.A.1.1. This is the first time these terms are introduced.
4.G.A.1.2. Ability to apply a deep understanding of this vocabulary will assist with drawing and identifying these shapes within two- dimensional figures.