Geometric elements (1)

created by Maria Jose Aparicio

1. GEOMETRIC ELEMENTS
POLYGONES
CIRCLE
ANGLES
LINES
POINTS

2. POINTS
•We may think of a point as a “dot” on a
piece of paper.
•We identify this point with a number or a
CAPITAL letter.
•A point has no length or width, it just
specifies an exact location.

3. ACTIVITY 1
Look this
picture and
create one
using only
points.

4. LINES
•STRAIGHT LINES don’t have a begginig or an
end.
•RAYS has a beginning point but it hasn’t an
end point.
•LINE SEGMENT has a beginning point and an
end point.
•CURVE LINES
•POLYGONAL LINES
•PARALLEL LINES
•SECANT STRAIGHT LINES
•PERPENDICULAR LINES

5. ACTIVITY 2
•USING YOUR SQUARE AND YOUR TRIANGLE
(RULES), DRAW LINES

6. ANGLES
•Two rays that share the same endpoint,
called vertex.
•Clasification by measurement:
–Acute<90º
–Right =90º
–Obtuse>90º
–Flat =180º
–Full =360º
•We use the protactor.

7. ANGLES
•ANGLE BISECTOR is a ray that divides an angle into two
equal angles.
–Place the compasses' point on the angle's vertex.
–Adjust the compasses to a medium wide setting. The exact width
is not important.
–Without changing the compasses' width, draw an arc across
each leg of the angle.
–Place the compasses on the point where one arc crosses a leg
and draw an arc in the interior of the angle.
–Without changing the compasses setting repeat for the other leg
so that the two arcs cross.
–Using a straightedge or ruler, draw a line from the vertex to the
point where the arcs cross
How to make it

8. ACTIVITY 3 and 4
•Use the protactor and clasify the angles.
•Draw angles.
•Draw the angle bisector.

9. POLYGONS
•A polygon is a closed figure made by
joining line segments.
•Polygons can be regular or irregular; o, .
–Triangles (3 sides)
–Quadrilateral (4 sides)
–Pentagon (5 sides)
–Hexagon (6 sides)
–Heptagon (7 sides)
–…

10. ACTIVITY
•Using polygons, draw yourself.

11. CIRCLE
•Radius: it’s the distance from the center
of the circle to the outside edge.
•Diameter: it’s the longest distance
across a circle.
•Circumference: it’s the perimeter, the
distance around the outer edge.
•Chord: it’s a line segment that connects
one point on the edge of the circle with
another point on the circle.
•Arc: it’s a segment of the circumference
of the circle.
•Sector: it’s a pie shaped portion of the
área of the circle.

12. ACTIVITY
•Draw a circle using the compass (12 cm of
diameter)
•Write the parts of the circle and the
circumference.
•Calculate the circumference  2xπxr
2