Respuesta :

Answer:

30

Step-by-step explanation:

Given:

QR= 45 mm

RS= 15, (1/3 of QR is 15).

QT is 90 mm

We must find ST.

Equation:

Use Segment Addition Postulate Theroem,

QR+RS+ST=QT

Subsitue the values we know

45+15+ST=90

60+ST=90

ST=30So ST length is 30 m
The answer is 30.
This is because QT is equal to all the measurements added up.
QR=45
RS=45/3
QT=90
ST=?

QR=45
RS=15
QT=90
ST=?

QR+RS=?
45+15= 60

QT-60=?
90-60=30

Therefore ST (the answer) is 30.