4.1. Two tangents intersect

Try these first

1. 1.

   What is a tangent in geometry?

   Hint

   Think about how it interacts with the curve.

2. 2.

   Define deflection angle.

   Hint

   Consider how two meeting straight lines form an angle.

3. 3.

   What is the formula for calculating the length of a curve?

   • L = RΔ(π/180)
   • L = R tan(Δ/2)
   • L = ΔT/R

   Hint

   It incorporates π and degrees.

4. 4.

   True or False: The deflection angle increases as the radius of the curve decreases.

   • True
   • False

   Hint

   Visualize the curve's tightness.

5. 5.

   Design a circular curve connecting two tangents, where the deflection angle is 60° and radius is 200 m. Calculate the tangent distance and length of the curve.

   Hint

   Remember to split the angle used in the tangent formula.

6. 6.

   Calculate the chainage of a point of tangency if the point of intersection is at 300 m and the tangent length is 40 m.

   Hint

   Think about how chainage is adjusted with tangent length.