"Rhombus" PPT download

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"Rhombus" PPT download

Part 1: Definition of rhombus:

A set of parallelograms with equal adjacent sides is called a rhombus;

Quadrilateral ABCD is a rhombus

How to use origami and cutting methods to quickly and accurately cut out a diamond-shaped piece of paper?

Ask the students to take out the prepared rectangular paper and fold it in half and then again according to the picture below, then cut it along the dotted line in the picture, and open it to get a rhombus.

Diamond PPT, Part 2: Verification

It is known that quadrilateral ABCD is a rhombus

Equal line segments:

AB=CD=AD=BC

OA=OC OB=OD

Congruent angles:

∠DAB=∠BCD ∠ABC =∠CDA

∠AOB=∠DOC=∠AOD=∠BOC =90°

∠1=∠2=∠3=∠4 ∠5=∠6=∠7=∠8

Isosceles triangles are:

△ABC △DBC △ACD △ABD

Right triangles are:

Rt△AOB Rt△BOC Rt△COD Rt△DOA

Congruent triangles are:

Rt△AOB ≌ Rt△BOC≌ Rt△COD ≌ Rt△DOA

△ABD≌△BCD △ABC≌△ACD

Rhombus PPT, part 3 content: Properties of rhombus:

(1) A rhombus has all the properties of a parallelogram;

(2) All four sides of a rhombus are equal;

(3) The two diagonals of a rhombus are perpendicular to each other, and each diagonal bisects a set of opposite angles;

(4) The rhombus is an axially symmetrical figure.

[Formula for area of ​​rhombus]

A rhombus is a special parallelogram, so can the area of ​​a rhombus be calculated using the parallelogram area formula?

Think about it: knowing the lengths of the two diagonals of a rhombus, can we find its area?

The area of ​​a rhombus = base × height = half the product of the diagonals

Diamond PPT, Part 4: Apply what you have learned

1. It is known that the perimeter of the rhombus is 12, then its side length is ().

2. In rhombus ABCD, the diagonal angles AC=6 and BD=8, then the perimeter of the rhombus = ( ) and the area = ( ).

3. In rhombus ABCD, O is the intersection point of the two diagonals. It is known that AB=5cm and AO=4cm. Find the lengths of the two diagonals AC and BD.

Rhombus problems can be solved by transforming them into right triangle or isosceles triangle problems

Diamond PPT, part 5: review summary

What did you learn in this lesson?

1. The definition of rhombus.

2. Properties of rhombus.

3. Area: S rhombus = base × height = half of the product of diagonals

Test in class

(1) Question 5 on page 102 of the textbook

(2) Known: As shown in the figure, AD bisects ∠BAC, DE∥AC intersects AB at E, DF∥AB intersects AC at F. Verify: the quadrilateral AEDF is a rhombus;

Keywords: Free download of Hebei Education Edition mathematics PPT courseware for eighth grade volume 2, diamond-shaped PPT download, .PPT format;

For more information about the "Rhombus" PPT courseware, please click on the Diamond PPT tab.

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Update Time: 2024-10-03

This template belongs to Mathematics courseware Hebei Education Edition Eighth Grade Mathematics Volume 2 industry PPT template

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