Respuesta :

D. 109.2
A triangle equals 180° and angle F is an obtuse angle therefore it can’t be 90° or lower.
180° - 109.2° = 70.8°
The smaller angles would each equal 35.4°

Answer:

109.2 degrees

Step-by-step explanation:

Use the cos law to find angle F

3.1^2 = 2^2 + 1.8^2 - 2 (2)(1.8) cos F

shows cos f = -.329

arc cos( - .329) = angle F =109.2 degrees