the measurement of an angle is 5times the measurement of its supplement.what is the measurement of the angle?

let the angle be Ø

then its supplement is 180-Ø

Ø = 5(180-Ø)
Ø = 900 - 5Ø
6Ø = 900
Ø = 150

so the angle is 150° and its supplement is 30°

check:
is 150 five times 30 ? , YES