Get expert insights and reliable answers to your questions on IDNLearn.com. Receive prompt and accurate responses to your questions from our community of knowledgeable professionals ready to assist you at any time.

6. From a certain point in front of the CN Tower, the
angle of elevation to the top is 65°. From a point
56.6 m closer, the angle of elevation is 70°. Calculate
the height of the CN Tower to the nearest tenth of
a metre.


Sagot :

Certainly! Let's solve the problem step-by-step:

Given:
1. The angle of elevation to the top of the CN Tower from the first point is 65°.
2. From a position 56.6 meters closer, the angle of elevation is 70°.

Let's denote:
- [tex]\( h \)[/tex] as the height of the CN Tower.
- [tex]\( d \)[/tex] as the horizontal distance from the original point to the base of the tower.

### Step 1: Establish the trigonometric relationships

From the first point:
Using the angle of elevation of 65°, we can write:
[tex]\[ \tan(65^\circ) = \frac{h}{d} \][/tex]
Thus,
[tex]\[ h = d \cdot \tan(65^\circ) \][/tex]

From the closer point:
Now, 56.6 meters closer to the tower, the angle of elevation is 70°. Therefore:
[tex]\[ \tan(70^\circ) = \frac{h}{d - 56.6} \][/tex]
Thus,
[tex]\[ h = (d - 56.6) \cdot \tan(70^\circ) \][/tex]

### Step 2: Solve for [tex]\( d \)[/tex]
We have two expressions for [tex]\( h \)[/tex]:
[tex]\[ d \cdot \tan(65^\circ) = (d - 56.6) \cdot \tan(70^\circ) \][/tex]

Let's set up the equation:
[tex]\[ d \cdot \tan(65^\circ) = d \cdot \tan(70^\circ) - 56.6 \cdot \tan(70^\circ) \][/tex]

Rearrange to isolate [tex]\( d \)[/tex]:
[tex]\[ d \cdot \tan(65^\circ) - d \cdot \tan(70^\circ) = -56.6 \cdot \tan(70^\circ) \][/tex]

Factor [tex]\( d \)[/tex] from the left side:
[tex]\[ d \cdot (\tan(65^\circ) - \tan(70^\circ)) = -56.6 \cdot \tan(70^\circ) \][/tex]

Finally, solve for [tex]\( d \)[/tex]:
[tex]\[ d = \frac{-56.6 \cdot \tan(70^\circ)}{\tan(65^\circ) - \tan(70^\circ)} \][/tex]

### Step 3: Compute the value of [tex]\( d \)[/tex]
Given the calculations,
[tex]\[ d \approx 257.9 \, \text{meters} \][/tex]

### Step 4: Compute the height [tex]\( h \)[/tex]
Now, using the initial tangent relation to find [tex]\( h \)[/tex]:
[tex]\[ h = d \cdot \tan(65^\circ) \][/tex]
[tex]\[ h \approx 257.9 \cdot \tan(65^\circ) \][/tex]

Performing this calculation,
[tex]\[ h \approx 553.1 \, \text{meters} \][/tex]

### Conclusion
The height of the CN Tower is approximately 553.1 meters to the nearest tenth of a meter.