TEKS 4.7E: Measure Unknown Angles
Decompose Angle Measurements
About this lesson
Learning Target: I can find the measure of an unknown angle.
Focuses On:
- Adding two smaller adjacent angles to find the total of the larger angle
- Finding the measurement of a smaller angle by subtracting the adjacent smaller angle from the total angle
Builds On:
4.7A:
Illustrate the measure of an angle as the part of a circle whose center is at the vertex of the angle that is “cut out” by the rays of the angle; angle measures are limited to whole numbers.
4.7B:
Illustrate degrees as the units used to measure an angle, where 1/360 of any circle is 1 degree and an angle that “cuts” n/360 out of any circle whose center is at the angle’s vertex has a measure of n degrees; angle measures are limited to whole numbers.
4.7C:
Determine the approximate measures of angles in degrees to the nearest whole number using a protractor.
Next Level:
5.5A:
Classify two‐dimensional figures in a hierarchy of sets and subsets using graphic organizers based on their attributes and properties.
Read More:
This lesson is designed to support student understanding of non-overlapping adjacent angles and how they can be used to find the measure of an unknown angle when given the measurements of the other two angles.
The two instructional blocks in this lesson are additive angles and adjacent angles.
In the first instructional block, students combine the angle measurements of two adjacent, non-overlapping angles to find the total of the larger angle.
The second instructional block has students find the measurement of a smaller angle when given the measurement of the adjacent angle and the total measurement of both smaller angles.
Scaffolds such as part-whole diagrams are built into the lesson to support student understanding.
Grade 4MathTEKS 4.7E