Obtuse angle: Has a measure that is greater that 90° but smaller that 180°
Acute angle: Has a measure smaller than 90°
Using these definitions, we answer the questions.
1. Angle VXW is the following angle:
It has a measure of 15° and thus is an acute angle. (because 15 is less than 90)
2.- the angle TXW is the following angle:
It has a measure of 105°, and thus is an obtuse angle (because 105 is greater than 90°)
3.- Angle SXV is:
We subtract VXW from SXW to get SXV which is 145°. And this is also an obtuse angle because its greater than 90°.
4.- Angle TXV is
We substract VXW from TXW to get the measure of TXV, which is 90°, and 90° is a right angle.