Search the courses, subjects, tracks, games and features, or jump straight to a page.
Learn it your way
A short class with Sarah and her students. The other ways are under More.
Sign up free to listen. Transcripts are free to read.
Today, we'll learn about angles of elevation. This is the angle formed from the horizontal line when you look up towards an object.
Why do we need to use trigonometry for angles of elevation?
Great question! We use trigonometry to calculate distances and heights that are hard to measure directly. For example, by knowing the height of a tower and measuring the angle of elevation from the ground, we can find how far away we are from the tower.
Can you give an example of that?
Sure! If a tower is 50 m tall and the angle of elevation is 30 degrees, we can use the tangent function to find the distance from the tower.
I remember that tan(θ) = opposite/adjacent!
Exactly! And in our example, the 'opposite' is the height of the tower. So, we set it up as tan(30°) = 50/distance.
And then we can solve for distance, right?
That's right! Let’s work on solving that together.
Continuing from our last discussion, if we apply the tangent equation, what do we find for distance?
We have tan(30°) = 50/distance, so distance = 50/tan(30°).
Correct! And what is tan(30°)? Do you remember?
Yes, it’s 1/sqrt(3) or about 0.577!
Excellent! Now plug that value into the distance equation.
So distance = 50/(1/sqrt(3)), which multiplies to 50*sqrt(3).
Which is approximately 86.6 m!
Fantastic! So this process can be used in various applications to determine distances.
Now, let's explore angles of depression. This is the angle formed when looking down from a certain height.
So, if we're at the top of a building looking down, that’s an angle of depression?
Correct! Just like angles of elevation, we can also use them in calculations.
Can we use the same trigonometric functions?
Yes, exactly! You’ll often find that you can still apply sin, cos, or tan based on the context.
Can you show an example of this?
Certainly! Let’s say you are on a cliff looking down at a boat with an angle of depression of 45 degrees. You can use similar tangent relationships to calculate the distance from the cliff you are at!
So it works the same as before?
Exactly! It’s just the idea of looking upward versus downward.
The branch of mathematics that deals with the relationships between the sides and angles of right-angled triangles.
The angle formed when looking up towards an object.
The angle formed when looking down towards an object.
Trigonometry is useful in various fields such as surveying, architecture, and engineering.
To find the distance from a tower given its height and the angle of elevation, use the formula distance = height/tan(angle). For instance, if a tower is 50m tall and the angle of elevation is 30°, the distance would be approximately 86.6 m.
During construction, architects may need to know the angle of elevation from a ground point to a structure to ensure proper height and alignment.
When looking up at a towering height, the angle of elevation gives us insight.
Imagine a climber at the top of a mountain. They look down and see a boat far away, realizing they need to calculate the distance using angles.
SOHCAHTOA helps remember sin = opposite/hypotenuse, cos = adjacent/hypotenuse, tan = opposite/adjacent.
E.D. for Elevation and Depression - Elevating our calculations upwards and depressing them downwards!
Term
Angle of Elevation
Click to flip
Term
Angle of Depression
Click to flip
Term
Tangent Function
Click to flip
The angle formed from the horizontal line of sight when looking upward towards an object.
The angle formed from the horizontal line of sight when looking downward towards an object.
A trigonometric function that relates the angle of a triangle to the ratio of the length of the opposite side to the length of the adjacent side.
This section explores the practical applications of trigonometry in measuring heights and distances.
In this section, we delve into how trigonometry is applied to determine heights and distances that are challenging to measure directly, as well as angles of elevation and depression. Practical examples illustrate these concepts in action.
In this section, we discuss the real-world applications of trigonometry, focusing on its utility in calculating heights and distances that are difficult to measure directly. Trigonometry helps us find angles of elevation and depression that are essential in various fields such as architecture, navigation, and surveying. An example illustrates the process of determining the distance to a tower by measuring the angle of elevation from a certain point on the ground and using the height of the tower. This section serves as a bridge between theoretical concepts and their practical implementations, demonstrating the importance of trigonometry in everyday life.