a parallelogram has side lenghts 20 cm and 25 cm. the diagonal opposite the obtuse angle measures 38 cm. what is the measure of the obtuse angle?

9514 1404 393

  114.8°

Step-by-step explanation:

The angles can be found using the Law of Cosines. It tells you ...

  c² = a² +b² -2ab·cos(C)

Then angle C can be found to be ...

  C = arccos((a² +b² -c²)/(2ab)) = arccos((20² +25² -38²)/(2·20·25))

  C = arccos(-419/1000) ≈ 114.77°

The measure of the obtuse angle is about 114.8°.

the diameter is 16 cm. are you a teacher?

step-by-step explanation:

i have no clue what you just said. write a question in english?