Math՚s: Division of a Line Segment: In a Ratio and Construction of Triangles (For CBSE, ICSE, IAS, NET, NRA 2022)

Doorsteptutor material for CBSE/Class-10 is prepared by world's top subject experts: get questions, notes, tests, video lectures and more- for all subjects of CBSE/Class-10.

Division of a Line Segment in the Given Ratio Internally

To divide a line segment in a given ratio say , follow the steps given below-

  • Step 1: Draw a ray making an acute angle with .
  • Step 2: Starting with , mark off points and on at equal distances from the point .
  • Step 3: Join and .
  • Step 4: Through (i.e.. the second point) , draw parallel to meeting at .
Division a Line Segment

The point divides the line in the ratio

Construction of Triangles

SSS Case (when three sides are given) - To construct a in which , and , follow the given steps

Construction of Triangles
  • Step 1: Take any of the sides as base. Here, is taken as a base. Draw .
  • Step 2: With as centre and radius , cut an arc.
  • Step 3: With as centre and radius cut another arc intersecting the arc of Step 2 at .
  • Step 4: Join and .

Then, is the required triangle.

SAS Case (when two sides and the included angle is given) - To construct a triangle in which , and

Construction of Triangles
  • Step 1: Take one of the sides as base (e. g. take . Draw
  • Step 2: At , construct an angle
  • Step 3: With as centre and radius draw an arc cutting at .
  • Step 4: Join

Then, is the required triangle.

ASA Case (when two angles and the included side is given) - To construct a triangle when two angles and one side are say , and , go through the following steps

Construction of Triangles
  • Step 1: Draw .
  • Step 2: At , construct
  • Step 3: At , construct meeting at .

Then, ABC is the required triangle.

Right Triangle Case (when the hypotenuse and a side is given) - To construct a right triangle , right angled at , side and hypotenuse , follow the steps given below

Construction of Triangles
  • Step 1: Draw
  • Step 2: At , construct
  • Step 3: With as centre and radius cut an arc intersecting at .
  • Step 4: Join

is the required triangle.

When two sides and a median corresponding to one of these sides, are given- To construct a in which , and median , follow the given steps

Construction of Triangles
  • Step 1: Draw
  • Step 2: Draw the perpendicular bisector of meeting AB in D.
  • Step 3: With as centre and radius cut an arc.
  • Step 4: With as centre and radius cut another arc intersecting the arc of Step 3 at
  • Step 5: Join AC and BC.

Then, is required triangle.

Developed by: