Question

Two adjacent angles of a parallelogram in the ratio 4:5. Find their measures

Answer 1

Let the angles be 4a and 5a

We know that adjacent angles of parallelogram are Supplementary,

=> 4a + 5a = 180

=> 9a = 180

=> a = 20

First angle = 20 × 4 = 80°

Second angle = 20 × 5 = 100°

Answer 2

$Let \: \: the \: two \: adjacent \: angles \: are \: in \: the \: ratio \: be \: x \\ \\ 1st \: angle \: = 4x \: \\ 2nd \: angle = 5x \\ 4x + 5x = 180 \: \: ( \: sum \: of \: a \: parallelogram \: is \: 180) \\ 9x = 180 \\ \\ x = \frac{180}{9} \\ x = 20 \\ \\ 1st \: angle \: = 4x = 4 \times 20 = 80 \: \\ 2nd \: angle \: = 5x = 5 \times 20 = 100 \: \: \: \: answer \\ Hope \: its \: help$