Chapter VI Concept of square and triangle and determining the measurement.

Chapter VIConcept of square and triangle and determining the measurement

Matematika SMP Kelas 1

(1. TRIANGLE)

Triangle is a plan figure limited by three sides and have three point of angles.

Triangle is usually symbolized by “ ”.

A. Definition of Triangle

a. Undefined triangle

B. Kinds of Triangles

1. Kinds of triangle based on the length of its side

c. Equilateral triangleb. Isosceles triangle


2. Kinds of triangle based on the angle

a. Acute triangle c. Right angled triangleb. Amblygon triangle

3. Kinds of triangle based on the angle

a. Acute triangle b. Obtuse triangle


The Size of one angle of Right-angled triangle is 90o.

C. Characteristics of special triangle

1. Right-angled triangle

Isosceles triangle can be formed by two right-angled triangles that are similar and congruent.Isosceles triangle has two sides that are similar and two similar angles.Isosceles triangle has one symmetric axis.

2. Isosceles triangle

Equilateral triangle is a triangle which the three sides are same.Equilateral triangle has three same sides and three same angels. Equilateral triangle has three symmetric axis.

3. Equilateral triangle


D. Amount of angles on triangle

1. The amount of angles on triangle is 180o

2.Calculate the size of one angle on triangle if two other angles is known


In each triangle always occurs that the amount of its two perpendicular is bigger than the third perpendicular.

E. Relation of sides and same angle on triangle

1. Inequality of triangle

In each triangle occurs the biggest angle that is located face to face with the longest side, whereas the smallest angle located face to face with the shortest side.

2. Relation of angle and the length of sides on triangle

The size of exterior angle of triangle is same with the amount of two interior angles that are not supplemented by the exterior angle

3. Relation of interior angles and exterior angle on triangle


Formula:K = a + b + c.

F. The circumference and the large of triangle

1. The circumference of triangle

Formula:

2. The large of triangle

There is a scarf shaped like isosceles triangle. The length of the same side is 12 cm and the length of another side is 30 cm. Jif the height of the scarf is 9 cm, find out:i) The circumference of the scarf;ii) The large of the scarf

3. Solving a problem that has relation with circumference and the large of triangle


(2. Rectangle)

Rectangle is a four sides plan figure with two pairs side are parallel and has four isosceles angle.

A . Rectangle

1. Definition of Rectangle

a. The sides that are face to face on a Rectangle are as long as and parallel.

b. The diagonals of a Rectangle are as long as and dividing into two same parts.

c. Each angle of Rectangle has same size and Isosceles (90o).

2. The characteristics of Rectangle

K = 2(p + l) atau K = 2p + 2l. dan L = p x l = pl.

3. The circumference and the large of Rectangle


Square is a quadrangle with four sides that the length are same and four isosceles angles.

B. Square

1. Definition of square

a. All characteristics of long square belongs to square.b. A square can occupy on its frame by eight ways.c. All sides of square are same.d. The angles of a square divided into two same parts by its diagonals.e. The diagonals of square are intersected in same length and forms an isosceles angle.

2. Characteristics of Square

K = 4s and L = s x s= s2.

3. The Circumference and the large of square


Parallelogram is a quadrangle figure that is formed by triangle and its reflection is twisted a half round (180o) on a midpoint of one of its side.

C. Parallelogram

1. Definition of parallelogram

a. The sides that are face to face on parallelogram has same length and parallelb. The angle that are face to face on parallelogram is same.c. The amount of pairs of neighboring angles on parallelogram is

180o.d. In parallelogram, the two diagonals divide into two same length of

it.

2. Characteristics of parallelogram


a. The Circumference of parallelogramKLMN = KL + LM + MN + KN

= KL + LM + KL + LM = 2(KL + LM)b. The large of parallelogram

L = base height = a t

3. The Circumference and the large of parallelogram


Rhombus is a quadrangle figure that is formed by isosceles triangle and its reflection after be reflected on its base.

D. Rhombus

1. Definition of rhombus

a. All sides of rhombus are same.b. The both diagonals on rhombus is symmetric axis.c. The both diagonal of rhombus divide two same parts each other and

perpendicular. d. On each rhombus the angles that are face to face have same big

and divide two same parts by its diagonals.

2. Characteristics of rhombus


K = AB + BC + CD + DAK = s + s + s + s

= 4 s’

The large of rhombus with the diagonals d1 dan d2 are

3. Circumference and large of rhombus


Kite is a quadrangle figure that is formed by combination of two isosceles triangles that the base is reflected with same length and enclosed.

E. The kite

1. Definition of Kite

a. The pairs of its side has same length.b. The pair of faced angle are same.c. One of its diagonal is symmetric axis.d. One diagonal of kite divides two same part and the other diagonal

divide two same length that is perpendicular.

2. Characteristics of kite


The circumference(K) and the large(L) of kite

with the short side is y the long side is x and

each diagonal is d1 and d2 is

K = 2(x + y)

3. The circumference ad the large of kite


Trapezium is a quadrangle figure which has appropriate pairing side

that are face to face and parallel.

F. Trapezium

1. Definition of trapezium

a. The circumference of trapezium determined by same way with

other plan figures, that is by summing the length of the sides that

limit the trapezium.

b. The large of trapezium= x The amount of parallel side x the

height

2. The circumference and the large of trapezium


„Thanks.“

Chapter VI Concept of square and triangle and determining the measurement.

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Transcript of Chapter VI Concept of square and triangle and determining the measurement.