Section 1.3: What is a Widget? (Good Definitions and CE)
Writing a definition is a common exercise during the early stages of Geometry. An excellent geometry definition will classify, quantify, and not have a counterexample. Once a term is defined, it can be used in subsequent definitions; for example, once parallel lines are defined, they can be used in the definition of a parallelogram.
There are four types of angles: acute, right, obtuse, and straight. Each name indicates a specific range of degree measurements. Congruent angles have equivalent measures. Adjacent angles share a vertex and a common side.
Supplementary angles are two angles whose sum is 180 degrees while complementary angles are two angles whose sum is 90 degrees. Supplementary and complementary angles do not have to be adjacent (sharing a vertex and side, or next to), but they can be.
Throughout Geometry, students write definitions and test conjectures using counterexamples. When writing definitions, counterexamples are useful because they ensure a complete and unique description of a term. If a counterexample does not exist for a conjecture (an if - then statement), then the conjecture is true.
There are four types of angles: acute, right, obtuse, and straight. Each name indicates a specific range of degree measurements. Congruent angles have equivalent measures. Adjacent angles share a vertex and a common side.
Supplementary angles are two angles whose sum is 180 degrees while complementary angles are two angles whose sum is 90 degrees. Supplementary and complementary angles do not have to be adjacent (sharing a vertex and side, or next to), but they can be.
Throughout Geometry, students write definitions and test conjectures using counterexamples. When writing definitions, counterexamples are useful because they ensure a complete and unique description of a term. If a counterexample does not exist for a conjecture (an if - then statement), then the conjecture is true.
Notes and Powerpoints
lesson_1.3.pdf | |
File Size: | 144 kb |
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Homework/Classwork
Homework: Section 1.3: What's a Widget worksheet #1-13
An extra practice worksheet is posted below.
An extra practice worksheet is posted below.
1.3.homework.glencoe.1.5.pdf | |
File Size: | 51 kb |
File Type: |