Answer:
The angle F of the triangle DEF measures 105 degrees.
Step-by-step explanation:
Given that triangle DEF has an angle D measuring 25 degrees and an angle E measuring 50 degrees, to determine what is the measure of angle F in degrees, knowing that the sum of the internal angles of every triangle gives a total of 180 degrees, we must perform the following calculation:
180 - 50 - 25 = F
130 - 25 = F
105 = F
Therefore, the angle F of the triangle DEF measures 105 degrees.
Answer:
No
Step-by-step explanation:


The basic angle for 1/2 is 60°, and cosines are negative in the first and third quadrant.
So, you take 180° - 60° = 120° to get the angle in the first quadrant, and 180° + 60° = 240° to get the angle in the third quadrant.
Since only 120° is an option, the answer is
B.