Plane shapes

1. GEOMETRY Plane Shapes

2. POLIGONS Polygons are plane shapes enclosed in rectilinear segments (their sides)   Depending on the number of sides they have they are called triangles, quadrilaterals, pentagons etc…

3. Triangle 3 sides . Quadrilateral 4 sides . Pentagon 5 sides .

4. Hexagon 6 sides . Heptagon 7 sides . Octagon 8 sides .

5. LABELLING THE PARTS OF A TRIANGLE Vertex : Are indicated by capital letters, A,B, C, etc. Sides : Can be AB, BC, CA, etc. or with small letters a, b, c, etc. In the latter case we use the letter of the opposite vertex. Angles: Are indicated by  etc.

6.   TRIANGLES Clasification by angles     Two angles of a triangle will always be acute angles. Depending on the other angle the triangle will be acute angled, right angled, or obtuse angled . obtuse acute right angled

7. TRIANGLES Clasification by sides A triangle with all three sides equal is called an equilateral . If it has two sides equal it is called an isosceles . If the three sides are different it is called a scalene . scalene equilateral isosceles

8. QUADRILATERALS CLASIFICATION OF QUADRILATERALS PARALLELOGRAMS (OPPOSITE SIDES PARALLEL) Rectangles Rhombuses Parallelograms NON PARALLELOGRAMS Trapeziums Trapezoids (only two sides parallel)  

9. REGULAR POLYGONS A regular polygon is one in which all sides are equal and all angles are equal. All regular polygons have a circumscribed circumference. n = number of sides

10. Triangle 3 sides . Quadrilateral 4 sides . Pentagon 5 sides .

11. Hexagon 6 sides . Heptagon 7 sides . Octagon 8 sides .

12. Enneagon or nonagon 9 sides . Decagon 10 sides .

13. CIRCUMFERENCE A circle is a shape with all points the same distance from its center . A circle is named by its center . Thus, the circle below will be called circle A since its center is at point A. The circumference is the line which makes the circle. A circle is the most perfect plane figure.