Find the exact value of Cos 240 degrees without a calculator. Show your work!
1 answer:
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Answer:
3 metres
Step-by-step explanation:
If we draw this out, we'll see that there are actually two similar right triangles (see attachment), which means that we can set up a proportion.
The height of the lookout tower corresponds to the height of the wooden column, while the shadow of the lookout tower corresponds to the shadow of the wooden column. We can then write:
(height of lookout tower) / (shadow of tower) = (height of column) / (shadow of column)
16 / 12 = 4 / x , where x is the shadow / unknown we want to find
Cross-multiply:
16x = 48
x = 3
The answer is thus 3 metres.
