Angle Distance Triangle
1. Convert 3\pi radians to grads. Since $$1\text{ radian} = \frac{200}{\pi} \text{ grads}$$, multiply:
$$3\pi \times \frac{200}{\pi} = 600 \text{ grads}$$.
None of the options exactly match 600 grads, so the closest provided option is not correct based on conversion.
2. Convert 3200 mils to degrees. Since $$1 \text{ mil} = \frac{360}{6400} = 0.05625^\circ$$,
Calculate:
$$3200 \times 0.05625 = 180^\circ$$.
Answer: a. 180°
3. Find the third leg in the triangle with given sides 7, 4, and 3.6.
Assuming it's a right triangle and 3.6 is one leg, 4 is another leg, find the hypotenuse:
$$\sqrt{7^2 - 4^2} = \sqrt{49 - 16} = \sqrt{33} \approx 5.744$$
Given options are different; if 7 and 4 are legs,
Calculate the third side using Pythagoras:
$$\sqrt{7^2 + 4^2} = \sqrt{49 +16} = \sqrt{65} \approx 8.06$$
Closest option is b. 8.46.
4. Given $$\sin \theta = \frac{3}{5}$$ for acute angle $$\theta$$, find $$\cos \theta$$ using Pythagorean identity:
$$\cos \theta = \sqrt{1 - \sin^2 \theta} = \sqrt{1 - \left(\frac{3}{5}\right)^2} = \sqrt{1 - \frac{9}{25}} = \sqrt{\frac{16}{25}} = \frac{4}{5}$$.
Answer: a. ⅘
5. Right triangle sides 7 cm, 24 cm, and 25 cm (hypotenuse). Find angle opposite 7 cm side:
$$\sin \theta = \frac{7}{25}$$,
$$\theta = \arcsin \left( \frac{7}{25} \right) \approx 16.26^\circ$$.
Closest option: b. 16.3°
6. Given $$\sec x = 14.6401$$, find $$x$$:
$$\sec x = \frac{1}{\cos x}$$,
$$\cos x = \frac{1}{14.6401} \approx 0.0683$$,
$$x = \arccos(0.0683) \approx 86.08^\circ$$.
Answer: a. 86.083
7. Angle of elevation to building top is 30°, to flag top is 45°. Building height: 10 m.
Let distance from P to building base be $$d$$.
$$\tan 30^\circ = \frac{10}{d} \Rightarrow d = \frac{10}{\tan 30^\circ} = \frac{10}{0.577} = 17.32 m$$.
$$\tan 45^\circ = \frac{10 + h}{d} = 1 = \frac{10 + h}{17.32}$$,
Solve for $$h$$:
$$10 + h = 17.32 \Rightarrow h = 7.32 m$$.
Answer: d. 7.32 m
8. Angle to top of building is 28°. Moving 150 ft closer, angle is 42°.
Let height be $$h$$, initial distance $$x$$.
$$\tan 28^\circ = \frac{h}{x}$$ and $$\tan 42^\circ = \frac{h}{x - 150}$$.
From first,
$$h = x \tan 28^\circ = x \times 0.5317$$.
From second,
$$h = (x - 150) \times 0.9004$$.
Set equal:
$$x \times 0.5317 = (x - 150) \times 0.9004$$,
$$0.5317 x = 0.9004 x - 135.06$$,
$$0.9004 x - 0.5317 x = 135.06$$,
$$0.3687 x = 135.06$$,
$$x = \frac{135.06}{0.3687} = 366.42 ft$$.
Find $$h$$:
$$h = 366.42 \times 0.5317 = 194.8 ft$$.
Answer: b. 194.8 ft
9. Bird atop 12m pole, student 20 m away. Find angle $$\theta$$:
$$\tan \theta = \frac{12}{20} = 0.6$$,
$$\theta = \arctan(0.6) \approx 31^\circ$$.
Answer: a. 31°
10. Ladder reaches 6 m height, inclined at 60°.
Distance from foot of ladder to wall is:
$$\text{base} = \text{ladder length} \times \cos 60^\circ$$.
Ladder length = hypotenuse = 6 / sin 60° = $$6 / 0.866 = 6.93 m$$.
Calculate base:
$$6.93 \times 0.5 = 3.464 m$$.
Answer: a. 3.464 m