One angle is equal to three times its supplement. The measure of the angle is (a) `130^@` (b) `135^@` (c) `90^@` (d) `120^@`

Explanation

`x+3x = 180`
`4x = 180`
`x = 180/4`
`x = 45 ` degrees for the smaller angle.
`180 – 45 = 135` degrees for the larger angle.
Proof:
`45+3 xx 45 = 180`
`45+135 = 180`
`180/2 = 90^@`