Unit 4: Geometry (Chapter 11-13)

In this unit I have learned about finding the area, area base, perimeter or circumference, and volume.

In the first chapter, which is chapter 11, I review the learning in primary. The area, the formula of the area in each shapes, such as square, rectangle, triangular, parallelogram and other shapes.
This is the list of shapes, properties and their formula:
1. Square

Properties: 

- All of the sides are equal

- 90˚ angels (all)

- 2 pair of parallel lines

Formula: 

side x side

2. Rectangular

Properties:

- 2 pair of parallel lines

- 2 pair of parallel lines

- 90˚ angels (all)

Formula:

length x width 

3. Parallelogram 

Properties: 

- 2 pairs of parallel lines

- 2 pairs of equal length side

Formula:

base x height

PS: base and height always make a perpendicular

4. Rhombus

Properties: 

- 2 pair of parallel lines

- 2 pairs of equal length side

- 90˚ all angels

Formula:

5. Kite

Properties: 

- 2 pairs of equal length sides

- 2 pairs of parallel lines

- the same length side meet together at the end

Formula:

6. Trapezoid (trapezium)

Properties: 

- 90˚ in one side

- 1 parallel lines

Formula:

In the next chapter, which is chapter 12. We learned about circle. Proving PI in circle and also area circumference and the method, the part of circle and also art of circle.

Part of circle:

1. Circle

: is the set of all points that are fixed distance from point called the Center

2. Diameter

is an interval joining 2 points on the circle and passes through the Center point and divided the circle to 2 parts

3. Radius

is half of the diameter or 1/4 of the circle

4. Arc: 

Is part of the circle

5. Chord 

5. Chord

Is a interval joining two points on the circle ( Not through the centre point)

6. Semi circle

is half of the circle

7. Segment

is the area made by chord and arc

8. Sector

made from 1 arc and 2 radius

9. Tangent

is a line that that touches a circle at only one point

Area and Perimeter for circle

Formula:

Area=

Perimeter (circumference)=

Next is the report of proving PI

MATHS WRITTEN REPORT

MATH’S

EXPERIMENT

FINDING VALUE OF PI

()

Jessieca Junesha

7 Asia

  

A. INTRODUCTION WHAT IS CIRCLE?-    CIRCLE IS A SET OF POINTS THAT ARE LINE WITH THE SAME DISTANCE TO EACH OTHER, FROM THE POINT THAT IS CALLED CENTER POINT (O).
CHARACTERISTIC:-    HAVE ONECENTER POINT
-    HAVE 360^O FROM THE CENTER POINT
-    HAVE NO SIDE
PARTS OF CIRCLE:-    DIAMETER: IS 2 JOINING POINT THAT PASSES THROUGH THE CENTER POINT, AND DIVIDED THE CIRCLE INTO 2 EVEN PART.
-    RADIUS: IS HALF OF THE DIAMETER THAT FORM ONE FOURTH OF THE CIRCLE
-    SEMI CIRCLE: IS HALF OF THE CIRCLE
-    SEGMENT: THE AREA THAT IS FORMED BY CHORD AND ARC.
-    SECTOR: MADE FROM 1 ARC AND 2 RADIUS
-    TANGENT: A LINE THAT THOUCHES A CIRCLE AT ONLY ONE POINT.
AREA AND PERIMETER?-    AREA IS THE MEASUREMENT OF THE WHOLE AREA OF THE INSIDE OF THE SHAPE.
-    PERIMETER OR CIRCUMFRENCE(USSUALLY CALLED FOR CIRCLE) IS THE LENGTH OF THE SIDE OF THE SHAPE.
HOW TO COUNT IT?-    AREA:  ² (RADIUS)
-    CIRCUMFERNCE: 2PI()?
-    PI is the number π is a mathematical constant, the ratio of a circle's circumference to its diameter, commonly approximated as 3.14159. It has been represented by the Greek letter "π" since the mid-18th century, though it is also sometimes spelled out as "pi"-    PI HAVE A VALUE OF 3.14 IN DECIMAL OR  IN FRACTION.
-    PI HAVE A FUNCTION TO HELP US TO FIND THE AREA AND CIRCUMFERENCE IN A CIRCLE.
 C.  PURPOSE OF EXPERIMENT (FOR FIND THE VALUE OF PI)
 -    OUR PURPOSE IS TO PROF THAT WITHOUT PI WE CANNOT FIND THE RIGHT ARE AND CIRCUMFERENCE OF CIRCLES
B.  PROCEDURE AND EQUIPMENT
 1.   EQUIPMENT
 TO MAKE THE CIRCLE WE NEED:-    COMPASS TO MAKE SURE THE CIRCLE HAVE THE SAME RANGE TO THE CENTER POINT AND ALSO TO DECIDE THE CENTER POINT
-    RULER TO MEASURE THE DIAMETER AND RADIUS SO WE KNOW THE AREA AND THE CIRCUMFERENCE.
2.   3.  PROCEDURE
HOW TO MAKE A CIRCLE?-    FIRST, DECIDE A CENTER POINT AND MAKE SURE THERE ARE PLENTY OF ROOM AROUND SO, WHEN WE MAKE IT, IT WILL NOT TOUCH THE THINGS AROUND.
-    THEN USE THE COMPAS AND MAKE A RANGE AS LONG AS WE WANT.
-    MAKE SURE THE POINTY PARK OF THE COMPASS IS IN THE CENTER POINT OF THE CIRCLE
-    DRW AROUND THE CENTER POINT WITH THE PENCIL IN THE COMPASS AND MAKE SURE IT DIDN’T MOVE AROUND.
-    DRAW A LINE ACROSS THE CENTER POINT USING THE RULER TO MAKE A DIAMETER
-    DRAW ANOTHER LINE ACROSS THE CENTER POINT TO MAKE RADIUS..  TABLE OF DATA

OBJECTS	DIAMETER	RADIUS	CIRCUMFERENCE	RELATIONSHIP CIRCUMFERENCE AND DIAMETER
	7.2 CM	3.6 CM	23.5CM	3.263 CM
	4.5 CM	2.25 CM	17 CM	3.7 CM
	9 CM	4,5 CM	29.5 CM	3.27 CM
	6 CM	3 CM	21 CM	2.3 CM
	2 CM	1 CM	7 CM	3.5 CM

 
D.  ANALYSIS AND DISCUSSION
-    PI is the same as circumference divided by diameter of the circle.
-    PI is use to find the circumference and area of the circle
-    To find the value of diameter, we need divide the circle into two
 E.  CONCLUSION AND REFLECTION
-    THE VALUE OF PI IS REALLY IMPORTANT TO FIND THE CIRCUMFERENCE AND AREA OF A CIRCLE.
-    CIRCLE KINDA EASY TO BE FINDED THE AREAA AND CIRCUMFERENCE
 

Next.... 3 method that I'm going to explain.

Art of Circle

 I make this pattern using compass and ruler: