polygons and circles (project in mathematics)
TRANSCRIPT
*Polygons And Circles
this presentation is written G
As your can see here……There are triangles, squares,rectangles,circles,and other plane figures. These plane figures are called polygons.A polygons is a closed plane figure bounded by line segments. A circle is an exception. It is not a polygon since it is not bounded by line segments.
Here are some examples of polygons.
on the other hand, the following figures are not polygons
Number of sides Name Figure
3 Triangle
4 Quadrilateral
5 Pentagon
6 Hexagon
7 Heptagon
Number of sides Name Figure8 Octagon
9 Nonagon
10 Decagon
11 Undecagon
12 Dodecagon
* Triangles and quadrilaterals are further classified into different kinds.Triangles are polygons with three sides, three angles,
and three vertices. The sum of the interior angles of a triangle is 180°. Triangles are classified in two ways…
*According to the Lengths of the
Sides
Triangle Characteristics FigureEquilateralTriangle (also called an equiangular Triangle)
• All sides are congruent or have equal lengths.
• Each angle measures 60° Therefore, all angles are congruent or have equal measures.
Isosceles triangle
• Two sides are congruent.
• Angles opposite congruent sides are congruent.
Scalene triangle• No sides are
congruent.• No angles are
congruent.
*According to the Angle Measures
Triangle Characteristics
Figure
Acute triangle All angles are acute.
Right triangle One angle is a right angle.
Obtuse triangle One angle is obtuse.
* are polygons with four sides, four angles, and four vertices. The sum of the interior angles of a quadrilateral is 360°
* Quadrilaterals
*The kinds of Quadrilaterals
Quadrilateral characteristics FigureRectangle • Two pairs of opposite
sides are congruent.• It contains four right
angles.
Square • Four sides are congruent.• It contains four right
angles.
Parallelogram • Tow pairs of opposite sides are congruent and parallel.
• Opposite angles are congruent.
Rhombus • Four sides are congruent.• Two pairs of opposite
sides are parallel.• Opposite angles are
congruent.
Trapezoid one pair of opposite sides is parallel.
A circle is a set of all points in a plane equidistant from a fixed point. The fixed point is called the center and the fixed distance from the center to a point on the circle Is the radius. A circle is named after its center. Recall that a circle is not a polygon because it is not bounded by line segments.Here is the example…..
A
O
C
D
F I1
In the figure on the previous page, the parts of a circle are illustrated.
1. center-point O2. Radius(plural:radii)-, A radius of a circle is a line segment from any point on the circle to its center. A radius of a circle measures half its diameter.3. chord- 4. diameter- A chore passing through the center of a circle is called a diameter. A diameter of a circle measures twice its radius.5. secant-I1 A secant is a line that intersects a circle at exactly two points.
6. Tangent-I2
Oh wait where is the circle…..There ok lets continuepoint of tangency-point A A tangent is a line that intersects a circle at exactly one point. This point is called the point of tangency.
By: Marigold So
Thaaaanks…
THE END