Trigonometry - How To Solve Right Triangles
TLDRThis educational video script guides viewers on solving a unique right triangle problem involving two smaller triangles within a larger one. The goal is to determine the height 'h' of the larger triangle. Given a side length of 500 and angles of 30 and 60 degrees, the script uses trigonometric ratios, specifically tangent, to set up equations. By leveraging the properties of 30-60-90 triangles and algebraic manipulation, the video demonstrates how to isolate and solve for 'h'. The process involves finding the variable 'x' first, which represents the side adjacent to the 60-degree angle, and then using it to calculate 'h'. The video concludes with the exact and approximate values for 'h', emphasizing the importance of understanding trigonometric functions and algebra in solving geometric problems.
Takeaways
- π The video discusses solving a special case of right triangles involving two smaller triangles within a larger triangle.
- π The goal is to calculate the value of 'h', the height of the larger right triangle.
- π’ Given measurements include a side length of 500 and angles of 30 and 60 degrees.
- π The speaker suggests labeling the sides and focusing on the small right triangle with a 60-degree angle.
- π§ The trigonometric ratio 'tangent' is used to set up equations involving 'h' and 'x', the adjacent side to the 60-degree angle.
- π The tangent of 60 degrees is known to be root three, which simplifies the equation to h = root three times x.
- π To find 'h', another equation involving 'h' and 'x' is needed, focusing on the larger right triangle with a 30-degree angle.
- β The tangent of 30 degrees is found to be root three divided by three, which is used in the second equation.
- βοΈ Both sides of the second equation are manipulated to isolate 'h' and to set up an equation that can be solved for 'x'.
- π’ Through algebraic manipulation, 'x' is found to be 250.
- π― With the value of 'x' known, 'h' can be calculated using the first equation, resulting in h = 250 times the square root of 3.
- π The decimal approximation of 'h' is approximately 433.01, but the exact answer is 250 times the square root of 3.
Q & A
What is the main goal of the video?
-The main goal of the video is to teach how to solve a special case of right triangles where two smaller triangles are within a larger triangle, with the objective of calculating the value of h.
What are the given measurements and angles in the problem?
-The given measurements are a side length of 500 units, and the angles are 30 and 60 degrees.
What is the first step suggested in the video for solving the problem?
-The first step suggested is to label the sides of the triangle, specifically labeling the side adjacent to the 60-degree angle as x.
What trigonometric ratios are mentioned in the video?
-The trigonometric ratios mentioned in the video are sine (s), cosine (c), and tangent (t), which are part of the 'sohcahtoa' mnemonic.
What is the tangent of 60 degrees in the context of the video?
-In the context of the video, the tangent of 60 degrees is equal to the square root of 3, which comes from the properties of a 30-60-90 triangle.
How does the video use the tangent of 60 degrees to form an equation?
-The video uses the tangent of 60 degrees to form the equation: tangent of 60 degrees = opposite side (h) / adjacent side (x), which simplifies to β3 = h/x.
What is the second equation derived from focusing on the larger right triangle?
-The second equation derived from the larger right triangle is: tangent of 30 degrees = opposite side (h) / adjacent side (x + 500), which simplifies to β3/3 = h/(x + 500).
What is the tangent of 30 degrees and how is it used in the video?
-The tangent of 30 degrees is 1/β3, which is derived from the properties of a 30-60-90 triangle. It is used in the video to form an equation involving h and x + 500.
How does the video solve for x?
-The video sets the two expressions for h equal to each other, resulting in an equation that, after simplification and algebraic manipulation, allows solving for x, which is found to be 250.
What is the final step to find the value of h?
-The final step is to substitute the value of x (250) back into one of the earlier equations for h, which gives h = β3 * 250.
What is the approximate decimal value of h given in the video?
-The approximate decimal value of h given in the video is approximately 433.01, which can be rounded to the nearest whole number.
Outlines
π Introduction to Solving Right Triangles with Nested Triangles
The video begins by introducing a unique problem involving two right triangles within a larger triangle. The objective is to calculate the height 'h' of the larger triangle. Given a side length of 500 and angles of 30 and 60 degrees, the presenter suggests labeling the sides and focusing on the smaller triangle with a 60-degree angle. The trigonometric ratio of tangent is highlighted, with the tangent of 60 degrees being equal to the opposite side (h) over the adjacent side (x). The presenter uses the properties of a 30-60-90 triangle to establish that the tangent of 60 degrees is root three, leading to the equation h = root three times x. This equation is then set aside for further use.
π Using Trigonometry to Solve for 'h' in the Larger Triangle
Moving on to the larger triangle with a 30-degree angle, the presenter applies the tangent function again, setting up an equation involving h, x, and 500. The tangent of 30 degrees is derived from the properties of a 30-60-90 triangle, resulting in the equation h = (root three / 3) * (x + 500). To eliminate fractions and simplify the equation, both sides are multiplied by 3(x + 500), leading to a new equation that relates h to x and 500. The presenter then equates the two expressions for h, resulting in a linear equation in terms of x. Solving for x gives the value of 250, which is a crucial step towards finding the value of h.
π― Final Calculations and Conclusion
With the value of x determined to be 250, the presenter substitutes this value back into the earlier equation for h, yielding h = root three times 250. The presenter then calculates a decimal approximation of h, which is approximately 433.01, and suggests rounding to the nearest whole number for practical purposes. The video concludes with the exact answer for h being 250 times the square root of three, summarizing the process of solving a right triangle problem with nested triangles using trigonometric ratios and algebraic manipulation.
Mindmap
Keywords
π‘Right Triangle
π‘Trigonometric Ratios
π‘Tangent (tan)
π‘30-60-90 Triangle
π‘Hypotenuse
π‘Adjacent Side
π‘Opposite Side
π‘SOHCAHTOA
π‘Equation
π‘Variable
Highlights
Introduction to solving right triangles with a special case involving two smaller triangles within a larger triangle.
Objective to calculate the value of 'h' in the larger right triangle with given measurements.
Labeling the sides of the triangle for clarity and ease of calculation.
Focusing on the small right triangle with a 60-degree angle to establish the first equation.
Utilization of the trigonometric ratio tangent to set up the equation for the 60-degree angle.
Understanding the tangent of 60 degrees using the properties of a 30-60-90 triangle.
Deriving the equation h = β3 * x from the tangent of 60 degrees.
Shifting focus to the larger right triangle to find a second equation for 'h'.
Using tangent of 30 degrees to establish a relationship between 'h', 'x', and the adjacent side.
Calculating the tangent of 30 degrees and simplifying the equation.
Eliminating fractions by multiplying both sides of the equation by the adjacent side.
Setting the two expressions for 'h' equal to each other to solve for 'x'.
Solving the equation to find the value of 'x' as 250.
Substituting the value of 'x' back into the equation to calculate 'h'.
Final calculation of 'h' as 250 * β3, providing both an exact and approximate decimal value.
Conclusion on how to solve a right triangle problem involving two triangles within a larger triangle.
Transcripts
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