RBSE Solutions for Class 7 Maths Chapter 10 Practical Geometry Ex 10.4

Rajasthan Board RBSE Solutions for Class 7 Maths Chapter 10 Practical Geometry Ex 10.4 Textbook Exercise Questions and Answers.

RBSE Class 7 Maths Solutions Chapter 10 Practical Geometry Ex 10.4

Question 1.
Construct ΔABC, given m∠A - 60°, m∠B = 30° and AB = 5.8 cm.
Answer:
Steps of consturction :

1. Draw a line segment AB = 5.8 cm
2. Construct ∠BAX = 60° at A
3. At B, construct ∠ABY = 30°.
4. Let the rays AX and BY interested at C.

Thus, ΔABC is the required triangle.

Question 2. 
Construct ∠PQR if PQ - 5 cm, m∠PQR = 105° and m∠QRP = 40°.
(Hint: Recall angle sum property of a triangle.)
Answer:
We can construct this triangle after finding ∠QPR using angle sum property of triangle. .

∠QPR = 180° - (∠PQR + ∠PRQ) 
∠QPR = 180° - (105° + 40°)
∠QPR = 180°- 145° = 35°

1. Draw a line segment PQ = 5 cm.
2. At P, construct ∠QPX = 35°.
3. At Q, construct ∠PQY = 105°.
4. Let the rays \(\overline{P X}\) and \(\overline{Q Y}\) intersected at R.

Thus, ΔPQR is the required triangle.

Question 3. 
Examine whether you can construct ΔDEF such that EF = 7.2 cm, m∠E = 110° and m∠F = 80°. Justify your answer.
Answer:
In given question,
m∠E = 110° and m∠F - 80° and m∠E + m∠F = 110° + 80° = 190° so, m∠E + m∠F > 180°
Since, sum of the three angles of a triangle is 180°, so given triangle DEF is not possible and ΔDEF cannot be constructed.