T = 40.0 N
angle = 25°
Trigonometric ratios:
sin(25°) = vertical component of the force / force
cos(25°) = horizontal component of the force / force
tan (25°) = vertical compoent of the force / horizontal component of the force.
From cos(25°) you can find the horizontal component of the force:
horizontal component of the force = force * cos(25°)
The force is the tension, 40.0 N.
horizontal component of the force = 40.0 N * cos (25°) = 36.25 N
Answer: 36.25 N