(2) Connect the intersection of two arcs into a straight line, which is the middle vertical line of the line segment.
2.( 1) Make an arc with the vertex of the angle as the center and any length as the radius, and the two sides of the intersection angle are E and F respectively.
(2) the intersection EF of two sides connecting an arc and an angle,
(3) Take E and F as the center, take the length of more than half of EF as the radius, and make an arc in the angle, and the intersection of the two arcs is C.
(4) The ray connecting the vertex of the angle with point C, what about this ray? Is the bisector of the angle.
3、? This is actually a vertical line of a known straight line. Let two villages be A and B, and a straight line represents the river.
Exercise:? (1) Take any point C on the other side of the river, and make an arc with one of the villages such as A as the center and AC length as the radius.
The intersection line is at c and d,
(2) With C and D as the center, the sum of more than half a CD as the radius, two arcs intersect at M and N respectively, connecting two points of MN, and the intersection line is in P, then the length of AP is the shortest path from Village A to the river.
In the same way, we can get the shortest path from village B to the river.
Look at the picture again in the process.