Graphic Design & Printing Technology- Letthegivenanglebe AOBbetweentwogivenlinesOA andOR
- With 0 ascentreandwithanyconvenientradius,drawanarccuttingOA
atCandOBatD. - NowwithCandDascentreand atanyconvenientradiusdrawarcsto
intersecteachotheratP.Drawalinethrough 0 andP,whichbisectsthe
givenangle AO.
TRIANGLES
ATriangleisaplanefigureboundedbythreestraightlinescontainingthree
angles. The sum of the three interior angles is 180o
- The sum of all the angles of a triangle is always 180°.
- The side on which it is supposed to stand is called its base and the angles
at the base are known as base angles. - The point where the other two sides meet is called a vertex and the angle
at the vertex is called a vertical angle. - The line drawn from the vertex and perpendicular to the base is called an
altitude. - The line joining the angular point of a triangle to the middle point of the
opposite of an angular point is called the Median.
TYPES OF TRIANGLES
i) Equilateral Triangle: It is that in which all the three sides are equal and
the three angles are equal.
ii) Isosceles Triangle: It is that in which two sides as well as the angle oppo-
site to them are equal.
Ill) Scalene Triangle: It has no sides or angle equal. The altitude may either
be within or outside the triangle.
iv) Right angled Triangle: It is that in which one angle is equal to 90° and the
side opposite to the right angle is called hypotenuse.