A geologist drew a scale drawing of a section of a quartz layer she saw in a cliff.

Question

The scale drawing of the layer is 4cm high and 28 cm long. If the actual layer is 0.2 m high, what is the area of the actual quartz layer section she saw?

Answer 1

First we should convert everything to the same units so that it's easier to think about. The 0.2 m is also 20 cm. So the actual layer height is 5 times the scale layer height. We should apply the same scale factor to the length. The actual length is 5 * 28cm, or 140 cm. To get the area, we multiply length and height. 20 * 140 = 2800. So the actual area is 2800 cm².