The DAV Maths Class 7 Solutions and **DAV Class 7 Maths Chapter 10 Worksheet 4** Solutions of Construction of Triangles offer comprehensive answers to textbook questions.

## DAV Class 7 Maths Ch 10 WS 4 Solutions

Question 1.

Draw a right triangle with hypotenuse of length 5 cm and one side of length 4 cm.

Answer:

Steps of Construction:

- Draw AB = 4 cm
- Draw ∠B = 90°
- Cut AC = 5 cm
- Join AC
- ∆ABC is the required right triangle.

Question 2.

Draw a right triangle with hypotenuse of length 4 cm and one side of length 2.5 cm. Measure the other two angles.

Answer:

Steps of Construction:

- Draw AB = 2.5 cm
- Draw ∠B = 90°
- Cut AC = 4 cm
- ∆ABC is the required right triangle.
- ∠A = 46° and ∠B = 44°

Question 3.

Construct a right triangle ABC in which AB = 5.8 cm, BC = 4.5 cm and ∠C = 90°.

Answer:

Steps of Construction:

- Draw BC = 4.5 cm
- Draw ∠C = 90°
- Taking B as centre, draw an arc of 5.8 cm, which cuts the right angle line at A.
- Join AC.
- ∆ABC is the required right triangle.

Question 4.

Construct a right triangle, having hypotenuse of length 5.4 cm and one of the acute angles of measure 30°.

Answer:

Steps of Construction:

- Draw AB = 4.5 cm
- Draw ∠B = 30°
- Draw angle A = 60°

[∵ ∠A = 90° – ∠B = 90° – 30° = 60°] - The two angle lines meet at C.
- ∆ABC is the required right triangle.

Question 5.

Construct a right triangle whose two sides containing the right angle measure 9 cm and 12 cm.

Answer:

Steps of Construction:

- Draw AB = 12 cm
- Draw ∠B = 90°
- Cut BC = 9 cm
- Join AC
- ∆ABC is the required right triangle.

### DAV Class 7 Maths Chapter 10 Value Based Questions

Question 1.

Construct a triangular poster of measurement 3 cm, 5 cm, 6 cm. Write the slogan “SAVE ELECTRICITY” on the poster.

(i) What should be done to save electricity?

Answer:

(i) Let us first draw a rough figure of given triangle.

Steps of construction:

Step 1. Draw a line segment BC = 5 cm.

Step 2. With B as centre and radius 3 cm, draw an arc of the circle. 3 cm

Step 3. With C as centre and radius 6 cm, draw another arc intersecting the previous arc at A.

Step 4. Join AB and AC to obtain the desired triangle.

(ii) To save electricity, switch off all the electronic gadgets when not in use or any other.