Question

Anybody know the answer?

Answer 1

We know that the sum of measures of internal angles in each quadrangle is 360°.

Look at the picture.

`\alpha+\beta+\gamma+\delta=360^o\ \text{and}\ \delta+\tau=360^o\\\\\text{therefore}\\\\\alpha+\beta+\gamma+\delta=\delta+\tau\ \ \ |-\delta\\\\\alpha+\beta+\gamma=\tau`

Therefore we have:

`\theta=35^o+83^o+23^o=141^o`

Answer: θ = 141 deg.