Question

Ina triangle ABC AB BC and CA are x, 3x+2,x+4unit respectively where x€N find the lengths of its sides????


(Hint Apply triangle - inequality) ​

Answer 1

Step-by-step explanation:

First note in all 3 + 4 + 5, that is, 12 points are used for forming the triangles. Since 3 points are needed to form a triangle, the total number of triangles (including the triangle formed by collinear points and as these collinear points will not form . triangles their number has to be subtracted from total) is

12

C

3

=220. But this includes the number of triangles formed by 3 points on AB =

3

C

3

= 1, the number of triangles formed by 4 points on BC =

4

C

3

= 4, and the number of triangles formed by 5 points on CA =

5

C

3

= 10.

Hence the required number of triangles

= 220-(1 + 4+10) =205.