In the figure, m and n are midpoints of rt and st. what is the length of mn?

a + b
b - a
2

 The correct option is (B) (b - a) units.

Step-by-step explanation:  Given that M and N are the mid-points of RT and ST.

We are to find the length of MN.

As shown in the figure,

the co-ordinates of the point T are (2c, 2d),

the co-ordinates of the point S are (2b, 0),

and

the co-ordinates of the point R are (2c, 2d).

Since M is the mid-point of TR, so the co-ordinates of M are

Also, N is the mid-point of TS, the co-ordinates of N are

Therefore, the length of the line segment MN calculated using distance formula will be

Thus, the required length of MN is (b - a) units.

Option (B) is correct.

step-by-step explanation:

the true ones are a b and d