F.5 Maths Trigonometry

2015-07-12 3:45 am

Picture: http://postimg.org/image/63y8ee53t/

I want to ask part (c) only.
**calculation is not necessary for my question.

In part(c), what is the meaning of "completely lies in triangle DEF"?
There are two cases.

Case 1: area of the card > area of triangle DEF
In this case the answer must be cannot.

Case 2: area of the card ≤ area of triangle DEF
Since the question has given the dimension of the card,
should we also consider the dimension of the triangle??

e.g. card: 5cm x 6cm
triangle DEF: 15cm x 3cm
Although the area of triangle is larger than the card,
since the height of the triangle is smaller than the width of the card,
so the answer still is cannot.

Is my thinking correct?
Please help, thank you!!!!

回答 (1)

邊位都好

2015-07-12 6:00 pm

✔ 最佳答案

Right, your thinking is correct.

"completely lies in triangle DEF" means totally lies inside the triangle.

2015-07-12 11:28:19 補充：
In general, if the card with dimension 5 x 6 can just fix in the triangle,

and this triangle having base b and height h, then it must satisfy 5/6 = b/h.

For example, if the base is 8, then the height must be at least 9.6.

👍 0 👎 0