can we sketch a triangle with 1:2:3 side-length ratio????

Intuitively, no. Think about the angles of the triangle.

If the sum of two sides is equal to the length of the last side, then the "triangle" is a straight line.

But the question is, when i draw it with compass, it becomes a triangle- -!!!

I don't think you are doing it right. ONe side 3, the sum of the other two is 3 also. No way a triangle.

A necklace is 60 centimeters long and the beads on the necklace are 50 millimeters apart. How many beads are on the necklace?

To find the number of beads on the necklace, we need to first convert the length of the necklace to millimeters since the distance between the beads is given in millimeters.

Given:
Length of the necklace = 60 centimeters
Distance between beads = 50 millimeters

To convert centimeters to millimeters, we multiply by 10:
60 centimeters * 10 = 600 millimeters

Now, we can find the number of beads by dividing the total length of the necklace by the distance between the beads:
Number of beads = Total length / Distance between beads
Number of beads = 600 millimeters / 50 millimeters

Dividing 600 by 50 gives us:
Number of beads = 12

Therefore, there are 12 beads on the necklace.