Як називається прилад який використовується для вимірювання кутів
Зміст:
1.9: Вимірювання кутів
Кут утворюється, коли два промені мають однакову кінцеву точку. Вершина є загальною кінцевою точкою двох променів, які утворюють кут. Сторони – це два промені, які утворюють кут. Малюнок \(\PageIndex\)
Позначте це | Скажи це |
---|---|
\(\angle ABC\) | Кут \(ABC\) |
\(\angle CBA\) | Кут \(CBA\) |
- Почніть з малювання горизонтальної лінії по всій сторінці, довжиною 2 дюйма.
- Помістіть кінцеву точку в лівій частині лінії.
- Помістіть транспортир на цю точку, таким чином, щоб лінія проходила через \( 0 ^\) мітку на транспортирі, а кінцева точка виявилася в центрі. Відзначте \( 50 ^\) на відповідній шкалі.
- Зніміть транспортир і з’єднайте вершину і \(50 ^\) mark.
This process can be used to draw any angle between \(0 ^\) and \(180 ^\) .
When two smaller angles form to make a larger angle, the sum of the measures of the smaller angles will equal the measure of the larger angle. This is called the Angle Addition Postulate. So, if B is on the interior of \(\angle ADC\) , then
\(\angle ADC = m \angle ADB + \angle BDC\)
How many angles are in the picture below? Label each one.
Solution
There are three angles with vertex \(U\) . It might be easier to see them all if we separate them.
So, the three angles can be labeled, ( \(\angle XUY\) or \(\angle YUX\) ), \(\angle YUZ\) (or \(\angle ZUY\) ), and \(\angle XUZ\) (or \(\angle ZUX\) ).
Measure the three angles from Example 1, using a protractor.
Solution
Just like in Example 1, it might be easier to measure these three angles if we separate them.
With measurement, we put an m in front of the \(\angle\) sign to indicate measure. So, \(m \angle XUY = 84^\) , \(m \angle YUZ = 42^\) and \(m \angle XUZ = 126^\) .
What is the measure of the angle shown below?
Solution
This angle is not lined up with 0∘, so use subtraction to find its measure. It does not matter which scale you use, as long as you are consistent.
Use a protractor to measure \(\angle RST\) below.
Solution
Lining up one side with \(0 ^\) on the protractor, the other side hits \(100 ^\) .
What is \(m \angle QRT\) in the diagram below?
Solution
Using the Angle Addition Postulate, \(m\angle QRT = 15^+30^=45^\) .
Review
1. What is \(m \angle LMN\) if \(m \angle LMO = 85^\) and \(m \angle NMO = 53^\) ?
2. If \(m \angle ABD = 100^\) , find \(x\) .
For questions 3-6, determine if the statement is true or false.
- For an angle \(\angle ABC\) , \(C\) is the vertex.
- For an angle \(\angle ABC\) , \(\overline\) and \(\overline\) are the sides.
- The \(m\) in front of \(m \angle ABC\) means measure.
- The Angle Addition Postulate says that an angle is equal to the sum of the smaller angles around it.
For 7-12, draw the angle with the given degree, using a protractor and a ruler.
For 13-16, use a protractor to determine the measure of each angle.
- Figure \(\PageIndex\)
- Figure \(\PageIndex\)
- Figure \(\PageIndex\)
- Figure \(\PageIndex\)
Review (Answers)
To see the Review answers, open this PDF file and look for section 1.5.
Vocabulary
Term | Definition |
---|---|
Angle | A geometric figure formed by two rays that connect at a single point or vertex. |
Protractor | A protractor is a tool used to measure an angle in terms of degrees. |
Vertex | A vertex is a point of intersection of the lines or rays that form an angle. |
Additional Resource
Video: Angle Basics
Activities: Angle Measurement Discussion Questions
Study Aids: Angles Study Guide
Practice: Measuring Angles
Real World: Angle Measurement
Recommended articles
- Article type Section or Page License CK-12 Show Page TOC No on Page
- Tags
- authorname:ck12
- program:ck12
- source@https://www.ck12.org/c/geometry
- source[translate]-k12-2136
1.9: Вимірювання кутів
Кут утворюється, коли два промені мають однакову кінцеву точку. Вершина є загальною кінцевою точкою двох променів, які утворюють кут. Сторони – це два промені, які утворюють кут. Малюнок \(\PageIndex\)
Позначте це Скажи це \(\angle ABC\) Кут \(ABC\) \(\angle CBA\) Кут \(CBA\) - Почніть з малювання горизонтальної лінії по всій сторінці, довжиною 2 дюйма.
- Помістіть кінцеву точку в лівій частині лінії.
- Помістіть транспортир на цю точку, таким чином, щоб лінія проходила через \( 0 ^\) мітку на транспортирі, а кінцева точка виявилася в центрі. Відзначте \( 50 ^\) на відповідній шкалі.
- Зніміть транспортир і з’єднайте вершину і \(50 ^\) mark.
This process can be used to draw any angle between \(0 ^\) and \(180 ^\) .
When two smaller angles form to make a larger angle, the sum of the measures of the smaller angles will equal the measure of the larger angle. This is called the Angle Addition Postulate. So, if B is on the interior of \(\angle ADC\) , then
\(\angle ADC = m \angle ADB + \angle BDC\)
How many angles are in the picture below? Label each one.
Solution
There are three angles with vertex \(U\) . It might be easier to see them all if we separate them.
So, the three angles can be labeled, ( \(\angle XUY\) or \(\angle YUX\) ), \(\angle YUZ\) (or \(\angle ZUY\) ), and \(\angle XUZ\) (or \(\angle ZUX\) ).
Measure the three angles from Example 1, using a protractor.
Solution
Just like in Example 1, it might be easier to measure these three angles if we separate them.
With measurement, we put an m in front of the \(\angle\) sign to indicate measure. So, \(m \angle XUY = 84^\) , \(m \angle YUZ = 42^\) and \(m \angle XUZ = 126^\) .
What is the measure of the angle shown below?
Solution
This angle is not lined up with 0∘, so use subtraction to find its measure. It does not matter which scale you use, as long as you are consistent.
Use a protractor to measure \(\angle RST\) below.
Solution
Lining up one side with \(0 ^\) on the protractor, the other side hits \(100 ^\) .
What is \(m \angle QRT\) in the diagram below?
Solution
Using the Angle Addition Postulate, \(m\angle QRT = 15^+30^=45^\) .
Review
1. What is \(m \angle LMN\) if \(m \angle LMO = 85^\) and \(m \angle NMO = 53^\) ?
2. If \(m \angle ABD = 100^\) , find \(x\) .
For questions 3-6, determine if the statement is true or false.
- For an angle \(\angle ABC\) , \(C\) is the vertex.
- For an angle \(\angle ABC\) , \(\overline\) and \(\overline\) are the sides.
- The \(m\) in front of \(m \angle ABC\) means measure.
- The Angle Addition Postulate says that an angle is equal to the sum of the smaller angles around it.
For 7-12, draw the angle with the given degree, using a protractor and a ruler.
For 13-16, use a protractor to determine the measure of each angle.
- Figure \(\PageIndex\)
- Figure \(\PageIndex\)
- Figure \(\PageIndex\)
- Figure \(\PageIndex\)
Review (Answers)
To see the Review answers, open this PDF file and look for section 1.5.
Vocabulary
Term Definition Angle A geometric figure formed by two rays that connect at a single point or vertex. Protractor A protractor is a tool used to measure an angle in terms of degrees. Vertex A vertex is a point of intersection of the lines or rays that form an angle. Additional Resource
Video: Angle Basics
Activities: Angle Measurement Discussion Questions
Study Aids: Angles Study Guide
Practice: Measuring Angles
Real World: Angle Measurement
Recommended articles
- Article type Section or Page License CK-12 Show Page TOC No on Page
- Tags
- authorname:ck12
- program:ck12
- source@https://www.ck12.org/c/geometry
- source[translate]-k12-2136