GEOMETRY BY YADAV & GEETA

BASIC CONCEPTS

IMPORTANT TERMS POINT LINE LINE SEGMENT RAY PLANE …………

POINT. A POINT OCCUPIES A POSITION AND ITS LOCATION CAN BE DETERMINED. A POINT HAS NO LENGTH, BREADTH OR THICKNESS. A POINT IS DENOTED BY A SINGLE CAPITAL LETTER SUCH AS A,B,P etc. AND READ ‘POINT A’ ‘POINT B’ etc. . B R S P Q P

II- LINE A LINE IS STRAIGHT AND EXTENDS ENDLESSLY IN BOTH DIRECTIONS. A LINE CAN BE NAMED AS Line L or AB

III-LINE SEGMENT A LINE SEGMENT IS A PORTION OF A LINE. IT HAS TWO END POINTS. THERE IS A UNIQUE LINE SEGMENT JOINING TWO GIVEN POINTS A&B. A B IT IS DENOTED AS AB

IV. RAY A RAY STARTS FROM A FIXED POINT AND EXTENDS ENDLESSLY IN ONE DIRECTION. A RAY IS A PART OF ALINE HAVING ONLY ONE END POINT O. THE END POINT IS CALLED INITIAL POINT OF RAY. A RAY IS NAMED BY IT’S INITIAL POINT O AND ONE MORE POINT ON IT. O A

INFINITELY MANY RAYS CAN BE DRAWN WITH A GIVEN POINT AS INITIAL POINT.

V. PLANE A PLANE IS A FLAT SURFACE WHICH EXTENDS INDEFINITELY IN ALL DIRECTIONS. A PLANE HAS LENGTH AND BREADTH, BUT NO THICKNESS. .

(I) BY WRITING A SINGLE SMALL LETER OF ENGLISH ALPHABET. A PLANE CAN BE NAMED AS (I) BY WRITING A SINGLE SMALL LETER OF ENGLISH ALPHABET. Z PLANE Z

(II) BY TAKING THREE DIFFERENT PONTS A,B,C IN THE PLANE BUT NOT ON THE SAME LINE. PLANE A B C.