mathematics
posted by abhigyan .
using glazed paper ,show that 3/7 and 9/21 are in prpportion.

The way to proceed is:
1. plot the two points (3,7) and (9,21) on graph paper
2. join the two points with a straight line (using a straightedge)
3. If the line passes through the origin, then the two ratios are in proportion.