How many meters are the 20-meter-long bamboo poles on the vernal equinox, summer solstice, autumn equinox and winter solstice?

A 20-meter-long bamboo pole is 20 meters at the vernal equinox and autumnal equinox, 2 meters at the summer solstice and 30 meters at the winter solstice. In the northern hemisphere, at the vernal equinox or autumnal equinox, the shadow of a one-meter bamboo pole is one meter long. In summer solstice, the shadow of a one-meter-long bamboo pole is 0. 1 meter long. During the winter solstice, the shadow of one meter bamboo pole is about 1.5 meters long. From vernal equinox to summer solstice or from summer solstice to autumn equinox, the shadow length of one meter bamboo pole is between 0. 1 m and 1 m. From the autumnal equinox to the winter solstice or from the winter solstice to the vernal equinox, the shadow length of a one-meter bamboo pole is between one meter and 1.5 meter.