Obtuse angle kitne degree ka hota hai?

Obtuse angle (अधिक कोण) 90 degree se bada aur 180 degree se chhota hota hai. Jaise 100°, 120°, ya 150°.

Adjacent angle in Hindi kya hota hai?

Adjacent angle ko Hindi mein आसन्न कोण (Aasanna Kone) kehte hain. Yeh do aise angle hote hain jinka ek vertex (kone ka point) aur ek arm (bhuja) common hoti hai.

What is the difference between an obtuse angle and a reflex angle?

An obtuse angle is between 90° and 180°, while a reflex angle is larger, measuring between 180° and 360°.

What are complementary and supplementary angles?

Complementary angles are any two angles that add up to 90 degrees. Supplementary angles are any two angles that add up to 180 degrees.

What is the perimeter of a rectangle in Hindi?

Perimeter of a rectangle ko Hindi mein 'आयत का परिमाप' (Aayat ka Parimaap) kehte hain. Iska formula hota hai: 2 × (Length + Breadth) ya 2 × (लंबाई + चौड़ाई).

Types of Angles: Names, Measurements, Hindi Meaning, and Project Ideas

An angle is formed when two rays share a common starting point called a vertex. The main types of angles are acute, right, obtuse, straight, reflex, and complete angles. In Hindi, an angle is called कोण (Kone), and adjacent angles are known as आसन्न कोण (Aasanna Kone).

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Complete List of Angles and Measurements

Angles are measured in degrees using the symbol degree. The size of an angle tells you how far one line has rotated away from the other around the vertex.

Angle Name	Hindi Name	Degree Measurement	Real-Life Example
Zero Angle	शून्य कोण (Shoonya Kone)	Exactly 0°	Both hands of a clock together at 12:00
Acute Angle	न्यून कोण (Nyoon Kone)	More than 0° and less than 90°	An open pair of scissors, a slice of pizza
Right Angle	समकोण (Samkone)	Exactly 90°	Corner of a textbook, corner of a room
Obtuse Angle	अधिक कोण (Adhik Kone)	More than 90° and less than 180°	Open laptop screen, roof of a house
Straight Angle	ऋजु कोण / सरल कोण (Riju Kone)	Exactly 180°	Straight ruler, clock hands at 6:00
Reflex Angle	प्रतिवर्ती कोण (Prativarti Kone)	More than 180° and less than 360°	Outer angle of an open book
Complete Angle	सम्पूर्ण कोण (Sampoorna Kone)	Exactly 360°	One full circle, clock hand making a full round
Adjacent Angles	आसन्न कोण (Aasanna Kone)	Two angles sharing one common arm and vertex	Two adjacent slices in an uncut pizza
Complementary Angles	पूरक कोण (Poorak Kone)	Two angles whose sum is 90°	30° and 60° together
Supplementary Angles	संपूरक कोण (Sampoorak Kone)	Two angles whose sum is 180°	110° and 70° together on a straight line
Co-Interior Angles	सह-अंतः कोण (Sah-Antah Kone)	Angles on the same side inside parallel lines	Interior corners in a C or U shape (sum is 180°)

Special Angle Pairs You Need to Know

When two or more angles appear together, they form special pairs that are commonly asked in Class 5, 6, and 7 maths exams.

Adjacent Angles (आसन्न कोण): Two angles placed side-by-side that share a common vertex and one common side, with no overlap.
Linear Pair: Adjacent angles on a straight line that always add up to 180 degrees.
Vertically Opposite Angles (शीर्षाभिमुख कोण): Opposite angles made when two straight lines cross each other (X shape). They are always equal.
Co-Interior Angles (सह-अंतः कोण): Angles inside two parallel lines cut by a transversal on the same side. Their sum is always 180 degrees.

How to Measure and Draw Angles Using a Protractor

A protractor (also called a D-scale) has two sets of numbers running from 0 to 180 degrees. Follow these simple steps to measure and draw any angle accurately.

Step 1: Place the baseline of your protractor along the bottom ray of the angle.
Step 2: Match the center point of the protractor perfectly with the vertex of the angle.
Step 3: Look at the 0 degree mark on the line you lined up. Follow that scale (inner or outer) upward.
Step 4: Read the number where the second ray crosses the curved edge of the protractor.
To draw an angle: Draw a straight baseline with a ruler, mark the vertex point, put the protractor center on that mark, place a dot at your desired degree, and connect the dot to the vertex using your ruler.

Easy Maths Project Ideas on Angles for School Charts and Models

If you need to make a maths project or working model for Class 5, Class 6, or Class 7, here are four easy ideas using items at home:

Paper Plate Angle Wheel: Take two paper plates of different colors (for example, blue and yellow). Cut a single slit from the edge to the center on both. Slide them into each other along the slit. Rotating one plate shows acute, right, obtuse, straight, and reflex angles clearly.
Matchstick or Toothpick Chart: Paste matchsticks on a cardboard sheet to form the letters of your name. Use a colored sketch pen to mark and label all the acute, right, and obtuse angles inside your letters.
Working Clock Model: Cut a circle from cardboard and attach two cardboard clock hands at the center using a split pin (paper fastener). Move the hands to show 3:00 (right angle), 2:00 (acute angle), 5:00 (obtuse angle), and 6:00 (straight angle).
Angle Yoga Chart: Draw stick figures doing simple yoga poses (like Tadasana or Vrikshasana) and label the angles formed by their arms and legs.

First Angle and Third Angle Projection Symbols

In technical drawing and geometry, projection symbols show how an object is drawn from the front, side, and top views. Both symbols use a truncated cone (frustum) and two concentric circles.

First Angle Projection Symbol: The side view of the cone is drawn first on the left, followed by the two circles on the right. Here, the object is placed between the observer and the projection plane.
Third Angle Projection Symbol: The two circles are drawn first on the left, followed by the side view of the cone on the right. Here, the projection plane lies between the observer and the object.

Common questions

Obtuse angle kitne degree ka hota hai?: Obtuse angle (अधिक कोण) 90 degree se bada aur 180 degree se chhota hota hai. Jaise 100°, 120°, ya 150°.
Adjacent angle in Hindi kya hota hai?: Adjacent angle ko Hindi mein आसन्न कोण (Aasanna Kone) kehte hain. Yeh do aise angle hote hain jinka ek vertex (kone ka point) aur ek arm (bhuja) common hoti hai.
What is the difference between an obtuse angle and a reflex angle?: An obtuse angle is between 90° and 180°, while a reflex angle is larger, measuring between 180° and 360°.
What are complementary and supplementary angles?: Complementary angles are any two angles that add up to 90 degrees. Supplementary angles are any two angles that add up to 180 degrees.
What is the perimeter of a rectangle in Hindi?: Perimeter of a rectangle ko Hindi mein 'आयत का परिमाप' (Aayat ka Parimaap) kehte hain. Iska formula hota hai: 2 × (Length + Breadth) ya 2 × (लंबाई + चौड़ाई).