Triangle – one of the most widespread geometrical figures. From tops of a triangle bisectors, heights and medians are built. If to cut out a triangle, for example, from cardboard, then the point of intersection of medians will be the center of gravity of this figure.
It is required to you
- - pencil;
- - ruler;
- - compasses.
Instruction
1. It is known that the median is the beam proceeding from a corner of a triangle and halving the opposite side. In any triangle them can be to three. To define a point of intersection of medians of a triangle, it is necessary to build these medians at first. For this purpose draw the required triangle and halve all three of its parties strictly. To divide the piece representing the party of a triangle into two equal parts, use compasses. Apply a so-called method of notches.
2. So take compasses and put its needle one way of a piece party. Develop compasses legs one distance more than a half of a piece and carry out an arch so that its ends came for the center of a piece. Now rearrange a compasses leg in the opposite end of the party of a triangle and again draw an arch – make notches. At you on both sides of a piece about two crossings of arches will turn out.
3. The following action take a ruler and connect these points of intersection. The line will pass precisely through the center of the party of a triangle. Do the same with other two parties of a triangle, that is designate their middle. The drawn pencil arches unnecessary now can be wiped a washing elastic band that they did not prevent further constructions.
4. Now carry out medians. For this purpose take a ruler again and draw the pieces connecting noted middle of the parties to tops of opposite corners. As a result you receive a point of intersection of three medians of a triangle.