Question

Please help me! Thanks.

Answer 1

`\huge \boxed{\mathrm{129\° }}`

Explanation:

Adjacent angles in a parallelogram add up to 180 degrees.

`\mathrm{m \angle A + m \angle B=180}`

Solving for
`\mathrm{m \angle B}`.

`\mathrm{m \angle B=180-m \angle A}`

`\mathrm{m \angle B}=180-51`

`\mathrm{m \angle B=129}`

Answer 2

129 is yr ANSWER........