Answer:
The length of rs is 19 units.
Explanation:
It is given that rd =7 units and ds = 12 units.
The point d is between points r and s on rs. It means the length of line segment rs is equal to the sum of length of lines segments rd and ds.

Substitute rd=7 and ds=12 in the above equation.


Therefore the length of rs is 19 units.