Physics · Surveying

Identify the correct statements regarding contour lines: i. Contour lines form sharp V-shaped curves across a valley line, with the convex side of the curve pointing towards the higher ground. ii. Contour lines form U-shaped curves across a valley line, with the convex side of the curve pointing towards the higher ground. iii. Contour lines form U-shaped curves across a ridge line, with the concave side of the curve pointing towards the higher ground. iv. Contour lines form sharp U-shaped curves across a ridge line, with the convex side of the curve pointing towards the higher ground.