If the measures of angles of a triangle are in the ratio of `3:4:5,` what is the measure of the smallest angle of the triangle? `25^0` (b) `30^0` (c) `45^0` (d) `60^0`

Explanation

Given: The angles of a triangle are in the ratio `3:4:5`.
Let the measure of the angles be `3x`, `4x`, `5x`
By the sum of the angles of a triangle`=180^@`
`3x+4x+5x=180`
`=>12x=180^@`
`=>x=180^@/12`
`=>x=15^@`
`therefore` Smallest angle`=3x`
`=3×15^@`
`=45^@`
Hence, the measure of the smallest angle of the triangle`=45^@`.