"Sum and Difference of Angles" PPT courseware

Description

"Sum and Difference of Angles" PPT courseware

1. Create a situation.

Classmates, we have learned some knowledge about angles.

I would like to ask: Can you draw angles of 30°, 60°, 90°, and 45° with the triangle in your hand?

2. Independent learning and cooperative inquiry

Study the sum and difference of angles graphically

Learning activity 1:

Observe the graph and think about the following questions:

1. What are the corners in the picture?

2. What is the relationship between these corners?

Learning activity 2: Bisectors of angles

practice

As shown in the figure, if ∠AOB= 82°, OP is the bisector of ∠AOC, OQ is the bisector of ∠COB, find the degree of ∠POQ.

Learning activity 3:

(1) It is known that ∠AOB is a right angle. What is the sum of ∠1 and ∠2?

Definition: If the sum of two angles is equal to 90°, then the two angles are called supplementary angles, or mutually supplementary for short.

(2) It is known that ∠DSE is a straight angle. What is the sum of ∠1 and ∠2?

Definition: If the sum of two angles is equal to 180°, then the two angles are called supplementary angles, or complementary angles for short.

Learning activity 4: Explore the nature of complementarity

Thinking 1: As shown in the figure, it is known that ∠2 and ∠1 are mutually supplementary, and ∠3 and ∠1 are mutually supplementary. So what is the relationship between ∠2 and ∠3? Why?

Thinking 2: As shown in the figure, it is known that ∠1 and ∠2 are mutually supplementary, ∠3 and ∠4 are mutually supplementary, ∠2= ∠4, so what is the relationship between ∠1 and ∠3? Why?

Look for it

Observe the graph below carefully and answer the following questions:

(1) How many pairs of complementary angles are there in the picture?

∠A and ∠B are mutually supplementary

∠A and ∠2 are mutually supplementary

∠1 and ∠B are mutually supplementary

∠1 and ∠2 are mutually supplementary

(2) Which pairs of angles in the figure are equal angles (except right angles)? Why?

∠B=∠2 (Supplementary angles of the same angle are equal)

∠A=∠1 (Supplementary angles of the same angle are equal)

Keywords: teaching courseware on the sum and difference of angles, download the Hebei Education Edition seventh-grade mathematics PPT courseware for the first volume, download the seventh-grade mathematics slide courseware, download the PPT courseware on the sum and difference of angles, .PPT format;

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Update Time: 2024-10-04

This template belongs to Mathematics courseware Hebei Education Edition Seventh Grade Mathematics Volume 1 industry PPT template

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