Geometry

GEOMETRY

Undefined terms • Point - indicates a location (or position) in space. • Line - set of points that extend indefinitely in opposite directions. o Line segment - has 2 endpoints o Ray - has 1 endpoint and one side extends endlessly in one direction.

• Plane - made up of points on a flat surface that extends in all directions.

PLANE FIGURES Are figures or shapes on a flat surface (or plane). Are two-dimensional (2D). o It has length and width.

Can have straight sides or curved sides. o Plane figure with straight sides are called Polygon.

TYPES OF POLYGON A. TRIANGLE - 3 sides

Classification of Triangle according to their sides • Equilateral Triangle - 3 sides are equal

Classification of Triangle according to their sides • Isosceles Triangle - 2 sides are equal

Classifications of Triangle according to their sides • Scalene Triangle - no sides are equal

What are the three classifications of triangle according to their sides?

Classifications of Triangle according to the measure of their interior angles

What is angle???

Review What is angle? - comes from the Latin word “angulus”, meaning “corner”. - angle is formed when two rays share a common vertex. A

B

C

Types of Angle • Right Angle • Acute Angle • Obtuse Angle

Classifications of Triangle according to the measure of their interior angles • Right Triangle - it has 1 right angle

Classifications of Triangle according to the measure of their interior angles • Acute Triangle - it has 3 acute angles

Classifications of Triangle according to the measure of their interior angles • Obtuse Triangle - it has 1 obtuse angle

TYPES OF POLYGON B. QUADRILATERAL - 4 sides

Different Quadrilaterals • Rectangle - has 4 sides; where 2 opposite sides are parallel.

Different Quadrilaterals • Square - is a special kind of rectangle that has 4 right angles and 4 congruent sides.

Different Quadrilaterals • Parallelogram - has 2 pairs of parallel sides. But in contrary, a parallelogram has no right angles.

Different Quadrilaterals • Rhombus - is a parallelogram that has 4 congruent sides.

Different Quadrilaterals • Trapezoid - has 1 pair of parallel sides.

Different Quadrilaterals • Trapezium - no parallel sides.

TYPES OF POLYGON C. PENTAGON - 5 sides 2

1

5

3

4

TYPES OF POLYGON D. HEXAGON - 6 sides 1 6

2

5

3

4

TYPES OF POLYGON E. HEPTAGON - 7 sides 7

1 2

6

5

3

4

TYPES OF POLYGON F. OCTAGON - 8 sides 8 7

1

6

2

5

3

4

TYPES OF POLYGON G. NONAGON - 9 sides 9

1 2

8

7

3 6

4 5

TYPES OF POLYGON H. DECAGON - 10 sides 10 9

1

8

2

7

3 6

5

4