Heights and Distances Level 3 Practice Quiz with Worked Solutions
This Level 3 set on Aptitude360 is a practice quiz on Heights and Distances. It tests whether you can turn multi-step word problems on angles of elevation and depression into right triangles and solve them. Every question has a worked solution, so you can trace a wrong step back to the exact triangle or ratio that caused it.
Topics covered in this Heights and Distances set
- Observers moving towards or away from a tower, such as a walking person, a car or a boat nearing a cliff
- Two observation points on the same side or on opposite sides of a tower or lighthouse
- Building and tower pairs with an angle of elevation to one top and an angle of depression to the other foot
- Ladders that slide along a wall, and kites with taut strings at changing angles
- Cloud and reflection problems over a still lake, plus aeroplanes and balloons in motion
- Broken trees, flagstaffs and statues on pedestals, and shadows cast by the sun or a lamp post
Key formulas for Heights and Distances problems
- Basic ratio: \( \tan\theta=\dfrac{h}{d} \)
- Two points on the same side, \( d \) apart, \( \alpha>\beta \): \( h=\dfrac{d\tan\alpha\tan\beta}{\tan\alpha-\tan\beta} \)
- Complementary angles from distances \( a \) and \( b \): \( h=\sqrt{ab} \)
- Points on opposite sides: \( d=h(\cot\alpha+\cot\beta) \)
- Cloud height, observer \( h \) above lake: \( H=\dfrac{h(\tan\beta+\tan\alpha)}{\tan\beta-\tan\alpha} \)
Revision tips for tougher elevation and depression questions
- Draw a labelled figure first and show clearly which side is the height and which is the horizontal distance
- Remember that the angle of depression from a point equals the angle of elevation of that point from below, because the horizontal lines are parallel
- In reflection problems, the image lies as far below the water surface as the object is above it
- Keep surds such as root three in the working until the final step to avoid rounding errors
Who should practise this Level 3 set
It suits aptitude aspirants who have already finished the basic and moderate levels of Heights and Distances and now want harder, multi-step trigonometry problems.