RD Sharma Solutions Chapter 11 Constructions Exercise 11.2 Class 10 Maths
Chapter Name | RD Sharma Chapter 11 Constructions |
Book Name | RD Sharma Mathematics for Class 10 |
Other Exercises |
|
Related Study | NCERT Solutions for Class 10 Maths |
Exercise 11.2 Solutions
1. Construct a triangle of sides 4 cm, 5 cm and 6 cm and then a triangle similar to it whose sides are (2/3) of the corresponding sides of it.
Solution
Steps of construction :
- Draw a line segment BC = 5 cm.
- With centre B and radius 4 cm and with centre C and radius 6 cm, draw arcs intersecting each other at A.
- Join AB and AC. Then ABC is the triangle.
- Draw a ray BX making an acute angle with BC and cut off 3 equal parts making BB1 = B1B2= B2B3.
- Join B3C.
- Draw B'C' parallel to B3C and C'A' parallel to CA.
2. Construct a triangle similar to a given ΔABC such that each of its sides is (5/7)th of the corresponding sides of ΔABC. It is given that AB = 5 cm, BC = 7 cm and ∠ABC = 50°.
Solution
Steps of construction :
- Draw a line segment BC = 7 cm.
- Draw a ray BX making an angle of 50° and cut off BA = 5 cm.
- Join AC. Then ABC is the triangle.
- Draw a ray BY making an acute angle with BC and cut off 7 equal parts making BB = B1B2 = B2B3 = B3B4 =B4B5 = B5B6 = B6B7
- Join B7 and C
- Draw B5C' parallel to B7C and C'A' parallel to CA.
3. Construct a triangle similar to a given ∠ABC such that each of its sides is 2/3rd of the corresponding sides of ΔABC. It is given that BC = 6 cm, ∠B = 50° and ∠C = 60°.
Solution
Steps of construction :
- Draw a line segment BC = 6 cm.
- Draw a ray BX making an angle of 50° and CY making 60° with BC which intersect each other at A. Then ABC is the triangle.
- From B, draw another ray BZ making an acute angle below BC and intersect 3 equal parts making BB1 =B1B2 = B2B2
- Join B3C.
- From B2, draw B2C' parallel to B3C and C'A' parallel to CA.
4. Draw a ΔABC in which BC = 6 cm, AB = 4 cm and AC = 5 cm. Draw a triangle similar to ΔABC with its sides equal to 3/4th of the corresponding sides of ΔABC.
Solution
Steps of construction :
- Draw a line segment BC = 6 cm.
- With centre B and radius 4 cm and with centre C and radius 5 cm, draw arcs intersecting each other at A.
- Join AB and AC. Then ABC is the triangle,
- Draw a ray BX making an acute angle with BC and cut off 4 equal parts making BB1= B1B2 = B2B3 = B3B4.
- Join B4 and C.
- From B3C draw C3C' parallel to B4C and from C', draw C'A' parallel to CA.
5. Construct a triangle with sides 5 cm, 6 cm and 7 cm and then another triangle whose sides are 7/5 of the corresponding sides of the first triangle.
Solution
Steps of construction :
- Draw a line segment BC = 5 cm.
- With centre B and radius 6 cm and with centre C and radius 7 cm, draw arcs intersecting each other at A.
- Join AB and AC. Then ABC is the triangle.
- Draw a ray BX making an acute angle with BC and cut off 7 equal parts making BB1 = B1B2 = B2B3 = B3B4 = B4B5 = B5B6 = B6B7.
- Join B5 and C.
- From B7, draw B7C' parallel to B5C and C'A' parallel CA.
6. Draw a right triangle ABC in which AC = AB = 4.5 cm and ∠A = 90°. Draw a triangle similar to ΔABC with its sides equal to (5/4)th of the corresponding sides of ΔABC.
Solution
Steps of construction :
- Draw a line segment AB = 4.5 cm.
- At A, draw a ray AX perpendicular to AB and cut off AC = AB = 4.5 cm.
- Join BC. Then ABC is the triangle.
- Draw a ray AY making an acute angle with AB and cut off 5 equal parts making AA1 = A1A2 = A2A3 =A3A4 = A4A5
- Join A4 and B.
- From A5, draw A5B' parallel to A4B and B'C' parallel to BC.
7. Draw a right triangle in which the sides (other than hypotenuse) are of lengths 5 cm and 4 cm. Then construct another triangle whose sides are 5/3 times the corresponding sides of the given triangle.
Solution
Steps of construction :
- Draw a line segment BC = 5 cm.
- At B, draw perpendicular BX and cut off BA = 4 cm.
- Join AC, then ABC is the triangle
- Draw a ray BY making an acute angle with BC, and cut off 5 equal parts making BB1 = B1B2 = B2B3 = B3B4 = B4B5
- Join B3 and C.
- From B5, draw B5C' parallel to B3C and C'A' parallel to CA.
8. Construct an isosceles triangle whose base is 8 cm and altitude 4 cm and then another triangle whose sides are 3/2 times the corresponding sides of the isosceles triangle.
Solution
Steps of construction :
- Draw a line segment BC = 8 cm and draw its perpendicular bisector DX and cut off DA = 4 cm.
- Join AB and AC. Then ABC is the triangle.
- Draw a ray DY making an acute angle with OA and cut off 3 equal parts making DD1 = D1D2 =D2D3 = D3D4
- Join D2
- Draw D3A' parallel to D2A and A'B' parallel to AB meeting BC at C' and B' respectively.
9. Draw a ΔABC with side BC = 6 cm, AB = 5 cm and ∠ABC = 60°. Then construct a triangle whose sides are (3/4)th of the corresponding sides of the ΔABC.
Solution
Steps of construction :
- Draw a line segment BC = 6 cm.
- At B, draw a ray BX making an angle of 60° with BC and cut off BA = 5 cm.
- Join AC. Then ABC is the triangle.
- Draw a ray BY making an acute angle with BC and cut off 4 equal parts making BB1= B1B2 B2B3=B3B4.
- Join B4 and C.
- From B3, draw B3C' parallel to B4C and C'A' parallel to CA.
10. Construct a triangle similar to ΔABC in which AB = 4.6 cm, BC = 5.1 cm, ∠A = 60° with scale factor 4 : 5.
Solution
Steps of construction :
- Draw a line segment AB = 4.6 cm.
- At A, draw a ray AX making an angle of 60°.
- With centre B and radius 5.1 cm, draw an arc intersecting AX at C.
- Join BC. Then ABC is the triangle.
- From A, draw a ray AX making an acute angle with AB and cut off 5 equal parts making AA1 = A1A2 = A2A3 = A3A4 =A4A5.
- Join A4 and B.
- From A5, drawA5B' parallel to A4B and B'C' parallel to BC.
Solution
Steps of construction :
- Draw a triangle XYZ with some suitable data.
- Draw a ray YL making an acute angle with XZ and cut off 5 equal parts making YY1= Y1Y2 = Y2Y3 = Y3Y4.
- Join Y4 and Z.
- From Y3, draw Y3Z' parallel to Y4Z and Z'X' parallel to ZX.
12. Draw a right triangle in which sides (other than the hypotenuse) are of lengths 8 cm and 6 cm. Then construct another triangle whose sides are 3/4 times the corresponding sides of the first triangle.
Solution
- Draw right ΔABC right angle at B and BC = 8 cm and BA = 6 cm.
- Draw a line BY making a cut angle with BC and cut off 4 equal parts.
- Join 4C and draw 3C' || 4C and C'A' parallel to CA.
13. Construct a triangle with sides 5 cm, 5.5 cm and 6.5 cm. Now construct another triangle, whose sides are 3/5 times the corresponding sides of the given triangle.
Solution
Steps of construction:
- Draw a line segment BC = 5.5 cm.
- With centre B and radius 5 cm and with centre C and radius 6.5 cm, draw arcs which intersect each other at A
- Join BA and CA.
- ΔABC is the given triangle.
- At B, draw a ray BX making an acute angle and cut off 5 equal parts from BX.
- Join C5 and draw 3D || 5C which meets BC at D.
- From D, draw DE || CA which meets AB at E.
14. Construct a triangle PQR with side QR = 7 cm, PQ = 6 cm and ∠PQR = 60°. Then construct another triangle whose sides are 3/5 of the corresponding sides of ΔPQR.
Solution
Steps of construction:
- Draw a line segment QR = 7 cm.
- At Q draw a ray QX making an angle of 60° and cut of PQ = 6 cm. Join PR.
- Draw a ray QY making an acute angle and cut off 5 equal parts.
- Join 5, R and through 3, draw 3, S parallel to 5, R which meet QR at S.
- Through S, draw ST || RP meeting PQ at T.
15. Draw a ΔABC in which base BC = 6 cm, AB = 5 cm and ∠ABC = 60°. Then construct another triangle whose sides are 3/4 of the corresponding sides of ΔABC.
Solution
Steps of construction:
- Draw a triangle ABC with side BC = 6 cm, AB = 5 cm and ∠ABC = 60°.
- Draw a ray BX, which makes an acute angle ∠CBX below the line BC.
- Locate four points B1, B2, B3and B4 on BX such that BB1 = B1B2=B2B3 = B3B4.
- Join B4C and draw a line through B3 parallel to B4C intersecting BC to C'.
- Draw a line through C' parallel to the line CA to intersect BA at A'.
16. Draw a right triangle in which the sides (other than the hypotenuse) arc of lengths 4 cm and 3 cm. Now, construct another triangle whose sides are 5/3 times the corresponding sides of the given triangle.
Solution
Steps of construction:
- Draw a right triangle ABC in which the sides (other than hypotenuse) are of lengths 4 cm and 3 cm. ∠B = 90°.
- Draw a line BX, which makes an acute angle ∠CBX below the line BC.
- Locate 5 points B1, B2, B3, B4 and B5 on BX such that BB1 = B1B2 = B2B3 = B3B4 = B4B5.
- Join B3 to C and draw a line through B5 parallel to B3C, intersecting the extended line segment BC at C'.
- Draw a line through C' parallel to CA intersecting the extended line segment BA at A'.
17. Construct a ΔABC in which AB = 5 cm, ∠B = 60°, altitude CD = 3 cm. Construct a ΔAQR similar to ΔABC such that side of ΔAQR is 1.5 times that of the corresponding sides of ΔACB.
Solution
Steps of construction :
- Draw a line segment AB = 5 cm.
- At A, draw a perpendicular and cut off AE = 3 cm.
- From E, draw EF || AB.
- From B, draw a ray making an angle of 60 meeting EF at C.
- Join CA. Then ABC is the triangle.
- From A, draw a ray AX making an acute angle with AB and cut off 3 equal parts making A A1 = A1A2 = A2A3.
- Join A2 and B.
- From A, draw A'B' parallel to A2B and B'C' parallel to BC.