true or false

1, there is only one midpoint for any given line segment

2, if AB+BC=AD then B lies between A and D

3, if AB+BC=AC then B is the midpoint of AC

4, If C is the midpoint of AB then AC=BC

5, if B belongs to Ox, A belongs to Oy, Ox and Oy are opposite then O is the midpoint of AB

Given K is the midpoint of AB 

If KA = 2x + 1 (cm)

   BK = x + 5 (cm ) then AB = ...... (cm )

Let ABCD be a trapezoid with bases AB, CD and O be the intersection of AC and BD. If the areas of triangle OAB, triangle OCD are 16cm², 40cm²respectively and M is the midpoint of BD, then the area of the triangle AMD is  .........cm².

Let ABCD be a trapezoid with bases AB, CD and O be the intersection of AC and BD. If the areas of triangle OAB, triangle OCD are 16cm², 40cm²respectively and M is the midpoint of BD, then the area of the triangle AMD is .........cm².

Let ABCD be a trapezoid with bases AB, CD and O be the intersection of AC and BD. If the areas of triangle OAB, triangle OCD are 16cm², 40cm²respectively and M is the midpoint of BD, then the area of the triangle AMD is  .........cm².

Bạn nào giúp mk vs!!!

Given K is the midpoint IJ If KI= 9 cm then IJ = cm 

Ghi kết quả thôi nhanh lên

Given a segment AB = 100cm. Let C be a point between A and B. Let M, N be respectively the midpoint of the segment BC, AC. Find the length of the segment MN.

Given the right triangle ABC (A^{^} = 90^o), BD is the bisector of the angle at B ( D of AC ). If AD = 6cm and AB = 12cm then the area of the right triangle ABC is ...... cm².