The earth receives energy from the Sun in the form of radiation . The Earth reflects about 30% of the incoming solar radiation. In polar areas, solar radiation strikes earth at a low angle. The more acute the angle at which the sunlight strikes, the more atmosphere that sunlight must pass through.
In ΔABC, D and E are points on side AB and AC respectively. DE is parallel to BC. If lengths of AD, DB and AE are 8 cm, 4 cm and 12 cm respectively, what is the length of AC?