Maths Lines and Angles part 10 (Questions 3: Related Angles) CBSE Class 7 Mathematics VII

TL;DR

Learn how to find the values of unknown angles by applying the properties of vertically opposite angles, linear pairs, and supplementary angles.

Transcript

hello friends this video on lines and angles part 10 is brought to you by exam feel calm no more fear from exam let's look at question number 7 find the values of the angles x y&z so in this diagram first of all let us focus on X so what do you see these are two intersecting lines which are intersecting at this point and this 55 degree and X are ve... Read More

Key Insights

• 🟰 Vertically opposite angles are always equal.
• 🔺 The sum of angles in a linear pair or supplementary angles is always 180 degrees.
• 🫥 The angles formed by intersecting lines are related through properties such as vertically opposite angles and forming straight lines.
• 💁 Adjacent angles that do not form a linear pair have a common vertex and side but do not add up to 180 degrees.

Questions & Answers

Q: How can you find the value of angle X using the properties of intersecting lines?

By recognizing that angles X and 55 degrees are vertically opposite, we can conclude that X equals 55 degrees.

Q: How are angles X and Y related in the given diagram?

Angles X and Y form a linear pair or supplementary angles, meaning their sum is 180 degrees. By substituting the value of X (55 degrees), we can solve for Y, which equals 125 degrees.

Q: What is the relationship between angles Z and Y in the second example?

Similar to the relationship between X and Y, angles Z and Y are also vertically opposite. Therefore, Z is equal to Y, which is 125 degrees.

Q: How can you find the value of angle X in the second example using intersecting lines?

By recognizing that the angle formed by the intersection of the two lines is a straight line, we can conclude that the sum of angles 40 degrees, X, and 25 degrees is 180 degrees. By solving this equation, X is determined to be 115 degrees.

Summary & Key Takeaways

• The video explains how to find the values of unknown angles using properties of intersecting lines, such as vertically opposite angles and linear pairs.

• By applying the property that vertically opposite angles are equal, the values of angles X, Y, and Z in a given diagram are determined.

• In another example, the video demonstrates how to find the values of angles X, Y, and Z by considering the properties of a straight line and vertically opposite angles.