How can I estimate and measure angles to 180 degrees?
How can I use a protractor to measure angles?
How can I understand a 1/4 turn is a right angle, a 1/2 turn as two right angles, a 3/4 turn is three right angles, a 3/4 turn is three right angles, and a full turn is the same as 4 right angles?
Content:
Students will know and understand:
Ray
Vertex
Protractor
Degrees
Inner Scale
Outer Scale
Acute Angle
Obtuse Angle
Straight Angle
Turn
Additive
Skills:
Students Will:
Estimate and measure angles with a protractor.
Estimate whether the measure of an angle is less than or greater than a right angle.
Use a protractor to draw acute and obtuse angles.
Relate 1/4, 1/2, 3/4, and full turns to the number of right angles.
4.MD.C.5. Recognize angles as geometric shapes that are formed wherever two rays share a common endpoint, and understand concepts of angle measurement:
4.MD.C.5a. 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 a circle is called a “one-degree angle,” and can be used to measure angles.
4.MD.C.5b. An angle that turns through n one-degree angles is said to have an angle measure of n degrees.
4.MD.C.6. Measure angles in whole-number degrees using a protractor. Sketch angles of specified measure.
4.MD.C.7. Recognize angle measure as additive. When an angle is decomposed into non-overlapping parts, the angle measure of the whole is the sum of the angle measures of the parts. Solve addition and subtraction problems to find unknown angles on a diagram in real world and mathematical problems, e.g., by using an equation with a symbol for the unknown angle measure.
4.G.A.1. Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures.
MP.1. Make sense of problems and persevere in solving them.
MP.2. Reason abstractly and quantitatively.
MP.3. Construct viable arguments and critique the reasoning of others.
MP.4. Model with mathematics.
MP.5. Use appropriate tools strategically.
MP.6. Attend to precision.
MP.7. Look for and make use of structure.
MP.8. Look for and express regularity in repeated reasoning.