WBBSE Solutions For Class 7 Maths Geometry Chapter 1

Geometry Chapter 1 Revision Of Old Lesson

Question 1. Choose the correct answer

1. The acute angle is

1. 30°
2. 90°
3. 105°
4. 270°

The acute Angle lies between 0° to 90°

∴ The option (1) 30° is the correct answer

Class 7 Maths Geometry Chapter 1 Solutions

2. The surface of the pyramid is.

1. Rectangle
2. Square
3. Triangle
4. None of these

∴ The option (3) triangle is the correct answer.

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3. The number of vertices of a cube is

1. 4
2. 6
3. 8
4. 12

∴ The option (3) 8 is the correct answer

Question 2. write true or false

1. Only one curved line can be drawn through two points. → False

2. Two straight lines can be drawn through two Fixed points → False

3. 120° is an obtuse angle → True

Class 7 Geometry Chapter 1 Questions

Question 3. Fill in the blanks

1. The greatest chord of a circle is known as the Diameter
2. 180° is called a straight angle
3. Many straight lines can be drawn through one fixed point.

Question 4. write the definition with a Figure of the Following

1. Adjacent angle

Adjacent angles: are two angles that share a common side and a common vertex, and do not overlap.

In the given diagram ∠ABD and ∠CBD are adjacent angles.

They share the common arm or common side BD and a common vertex B.

2. Vertically opposite angle

vertically opposite angles are angles that are opposite one another at a specific vertex and are created by two straight intersecting lines.

vertically opposite angles are equal to each other.

WBBSE Class 7 Maths Geometry Solutions

3. Reflex Angle:

A reflex Angle is an angle that is more than 180° and less than 360°

4. Straight Angle

A straight angle measures 180° and looks like a straight line

Mathematically

It is an angle whose arms lie in opposite directions from the vertex and they join together to form 180°.

5. Obtuse Angle

An angle that is larger than go but smaller than 180° is called an obtuse angle.

Question 5. Draw a line segment of length 10cm with a scale and divide it into four equal parts. Measure
Solution:

Line segment AB = 10cm

It is divided into ‘4’ equal parts.

Each part is divided into 2.5CM

AC = 2.5cm,

CD = 2.5 cm,

DE = 2.5 CM,

EB = 2.5 cm

∴ AB = AC+ CD +DE+EB

= 2·5+2·5+2·5+2·5

AB = 10cm

∴ The parts are equal AC = CD= DE = EB.

Class 7 Geometry Textbook Solutions 

Question 6. Draw an angle of 120° with the help of a protractor and divide it into four equal parts with the help of a compass.
Solution:

∠BOA = 120°

∠OAE = 30°

∠AOD = 60°

∠AOC = 90°

Question 7. Draw a triangle ABC and bisect each of the three angles and find if the angle bisectors are concurrent.
Solution:

Question 8. Draw a triangle ABC and bisect the sides BC, AC, and AB perpendicularly. If the three perpendicular bisectors are concurrent then name it’ Now with. center o and radius equal to the line segment AO draw a circle.
Solution:

Class 7 Maths Geometry Problems

Question 9. Draw a triangle PQR and from the three vertices P, Q, and R of the triangle, perpendicular PA, BQ, and RC are drawn on the sides QR, RP, and PQ respectively If the line segment PA, QB, and RC are concurrent.
Solution:

Question 10. A line segment AB of length 6cm is drawn. A point p is taken on the line segment AB. With the help of a scale and pencil compass draw a perpendicular PQ on AB at p.
Solution:

1. Draw a line segment AB of length 6cm
2. Draw a point ‘P’ on a line segment
3. Draw a perpendicular on ‘AB’.