4.MD.5. Recognize angles as geometric shapes that are formed 4.MD.5. the diagram below will help students understand that an angle measurement is not related to an area since the area between the 2 rays is wherever two rays share a common endpoint, and understand different for both circles let the angle measure is the same. concepts of angle measurement: a. 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 and “one-degree angle,” can be used to measure angles. b. An angle that turns through one-degree angles is said n to have an angle measure of degrees. n 4.MD.6. Measure angles in whole-number degrees using a 4.MD.6. Before students begin measuring angles with protractors, they need protractor. Sketch angles of specified measure. to have some experiences with benchmark angles. They transfer their understanding that a 360º rotation about a point makes a complete circle to recognize and sketch angles that measure approximately 90º and 180º. They extend this understanding and recognize and sketch angles that measure approximately 45º and 30º. They use appropriate terminology (acute, right, and obtuse) to describe angles and rays (perpendicular). 4.MD.7. Recognize angle measure as additive. When an angle is 4.MD.7. decomposed into non-overlapping parts, the angle measure of the Examples whole is the sum f the angle measures of the parts. Solve addition If the two rays are perpendicular, and subtraction problems to find unknown angles on a diagram in what is the value of m? real world and mathematical problems, e.g., by using an equation with a symbol for the unknown angle measure. Joey knows that when a are exactly on 12 and 1, the clock’s hands angle formed by the measures 30o. What is the clock’s hands measure of the angle formed when a are exactly on the clock’s hands 12 and 4?
4.MD.5. Recognize angles as geometric shapes that are formed wherever two rays share a common endpoint, and understand concepts of angle measurement: a. 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. b. An angle that turns through n one-degree angles is said to have an angle measure of n degrees. 4.MD.5. the diagram below will help students understand that an angle measurement is not related to an area since the area between the 2 rays is different for both circles let the angle measure is the same. 4.MD.6. Measure angles in whole-number degrees using a protractor. Sketch angles of specified measure. 4.MD.6. Before students begin measuring angles with protractors, they need to have some experiences with benchmark angles. They transfer their understanding that a 360º rotation about a point makes a complete circle to recognize and sketch angles that measure approximately 90º and 180º. They extend this understanding and recognize and sketch angles that measure approximately 45º and 30º. They use appropriate terminology (acute, right, and obtuse) to describe angles and rays (perpendicular). 4.MD.7. Recognize angle measure as additive. When an angle is decomposed into non-overlapping parts, the angle measure of the whole is the sum f 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.MD.7. Examples If the two rays are perpendicular, what is the value of m? Joey knows that when a clock’s hands are exactly on 12 and 1, the angle formed by the clock’s hands measures 30o. What is the measure of the angle formed when a clock’s hands are exactly on the 12 and 4?