Kesebangunan Pada Segitiga. Part 3, Contoh Perhitungan

Summary

This video tutorial provides a detailed explanation on solving problems related to similar triangles, focusing on a specific example involving triangles ABC and DEC. The lesson walks viewers through the process of calculating the unknown sides CD and BE using the properties of similar triangles and the corresponding side ratios. The solution involves applying cross-multiplication to solve for the missing values, demonstrating step-by-step calculations and providing a clear understanding of the topic. Viewers are encouraged to ask questions in the comments for further clarification.

Takeaways

• 😀 Recap of similar triangles concept from previous videos.
• 😀 The problem involves two similar triangles: triangle ABC and triangle DEC.
• 😀 The given side lengths are AD = 2, AB = 6, DE = 4, and CE = 6.
• 😀 The task is to find the lengths of CD and BE in the similar triangles.
• 😀 The proportionality rule for similar triangles is applied to find the unknowns.
• 😀 The first calculation uses the ratio of corresponding sides: CD/CA = DE/AB.
• 😀 By solving the proportion, the length of CD is found to be 4.
• 😀 The second calculation uses the equation AB + BE = DE/AB to find BE.
• 😀 After solving, the length of BE is found to be 3.
• 😀 The importance of cross-multiplication in solving for unknown side lengths is emphasized.
• 😀 The presenter invites viewers to leave any questions in the comments for further clarification.

Q & A

What is the focus of this lesson in the video?

The focus of the lesson is on the concept of similar triangles and how to calculate the lengths of sides in similar triangles using proportionality.

What does 'similar triangles' mean in the context of the video?

'Similar triangles' refer to triangles that have the same shape but may differ in size. Their corresponding sides are proportional, and their angles are equal.

Which triangles are discussed in this lesson?

The triangles discussed are triangle ABC and triangle DEC, which are similar to each other.

What is the first calculation that needs to be made in the problem?

The first calculation is to find the length of side CD in triangle ABC using the proportionality of corresponding sides.

What formula is used to find the length of CD?

The formula used is the proportionality of corresponding sides in similar triangles, which gives the equation: CD/CA = DE/AB.

How do we solve for CD in the equation?

To solve for CD, we substitute the known values into the equation, then cross-multiply to isolate CD and find its value.

What is the value of CD after solving the equation?

After solving the equation, the value of CD is 4.

What is the second calculation to be made in the problem?

The second calculation is to find the length of side BE in triangle ABC using the proportionality of corresponding sides.

What formula is used to find the length of BE?

The formula used is again the proportionality of corresponding sides in similar triangles, which gives the equation: AB + BE = DE/AB.

How do we solve for BE in the equation?

To solve for BE, we substitute the known values into the equation, then cross-multiply to isolate BE and find its value.