Angles
An angle is formed when two rays share a common endpoint, called the vertex. The amount of rotation from one ray to the other determines the size of the angle. Angles are measured in degrees, and there are several types of angles:
- Acute Angle: An angle that measures less than 90 degrees.
- Right Angle: An angle that measures exactly 90 degrees.
- Obtuse Angle: An angle that measures more than 90 degrees but less than 180 degrees.
- Straight Angle: An angle that measures exactly 180 degrees, forming a straight line.
- Reflex Angle: An angle that measures more than 180 degrees but less than 360 degrees.
Angles can be classified based on their relationship to each other:
- Adjacent Angles: Two angles that share a common vertex and a common side, but do not overlap.
- Complementary Angles: Two angles whose measures add up to 90 degrees.
- Supplementary Angles: Two angles whose measures add up to 180 degrees.
Understanding angles is important for various mathematical and real-world applications, such as geometry, trigonometry, and navigation.
Remember, the total measure of angles around a point is 360 degrees, and in a straight line is 180 degrees.
.◂Math Worksheets and Study Guides First Grade. Greater Than, Less Than
Study Guide
Greater Than, Less Than 
Activity Lesson
Greater Than or Less Than Ducks Worksheet/Answer key
Greater Than, Less Than Worksheet/Answer key
Greater Than, Less Than Worksheet/Answer key
Greater Than, Less Than Vocabulary/Answer key
Greater Than, Less Than
Activity LessonWorksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyVocabulary/Answer keyThe resources above cover the following skills:
Number and Operations (NCTM)
Understand numbers, ways of representing numbers, relationships among numbers, and number systems.
Develop understanding of the relative position and magnitude of whole numbers and of ordinal and cardinal numbers and their connections.
Grade 1 Curriculum Focal Points (NCTM)
Number and Operations: Developing an understanding of whole number relationships, including grouping in tens and ones
Children compare and order whole numbers (at least to 100) to develop an understanding of and solve problems involving the relative sizes of these numbers. They think of whole numbers between 10 and 100 in terms of groups of tens and ones (especially recognizing the numbers 11 to 19 as 1 group of ten and particular numbers of ones). They understand the sequential order of the counting numbers and their relative magnitudes and represent numbers on a number line.