Question

if ST=15 and RT = 40, then RS=

Answer 1

Reorder the lines.

ST = 15
TR = 40

Note that both of them have "T" in them. because of this, you can add ST and TR together to get RS.

S------T-------R (is how the line will look like).

Add ST and RT together.

15 + 40 = 55

RS = 55


hope this helps