Q1 of 7 Page 222

Let's divide a line segment of length 9 cm in three equal parts by scale and pencil compassed and let's measure the length of the parts by scale.

Given: Length of a line segment = 9cm

Steps of Construction


Step1: Draw a line segment AB = 9cm



Step 2: From point A, draw a line segment at any angle.



Step 3: Now, take the compass and keep the needle on point A, and set its width to a bit less than one third of the length of AX and mark the three arcs of same length.



Step 4: Label the last arc C.



Step 5: Take the compass and keep the needle on point C and take the width CB, draw an arc from A just below it.



Step 6: Now, set the width of AC in compass, draw an arc from B intersecting the arc drawn in step 5. This intersection point is D. Join D to B




Step 7: Using the same compass width as used in step 3 along AC, step the compass from D along DB and make 3 arcs across the line.



Step 8: Join C to B and draw the lines between the corresponding points along AC and DB.



Hence, the lines divide the given line segment into 3 equal parts and each part is of 3cm


More from this chapter

All 7 →
1

Rihana drew a straight-line segment PQ of length 10 cm I divided the line segment PQ in five equal parts by scale and compass. Let’s verify by scale which each part of segment is 2 cm or not.

 2

Ajij divided a line segment XY of length 12 cm in some parts in such a way that each part is of length 2.4 cm. First decide how many parts are there and then divide the line XY into that number of equal parts.

 3

Anoara drew a triangle ABC in her exercise book. We bisect side BC by compass and then the median AD. I trisect AD in AE, EF and FD. Now we join B and F by scale and extended it to X such that it intersect AC at X.

Measuring by scale we see,


AX= CX(Let’s put the number)


 4

Let’s divide a line segment of length 12.6 cm into 7 equals parts, by scale and compass. Using the above construction let’s draw an equilateral. Triangle of length 7.2 cm.