CBSE Class 10 Mathematics Constructions Notes Set B

CHAPTER 10 : CONSTRUCTIONS
CLASS X

PRE- REQUISITE KNOWLEDGE:
1. To construct the angle bisector of a given angle.
2. To construct the perpendicular bisector of given line segment.
3. To construct angle measures 300, 450, 600, 750, 900, 1050, 1200, 1350, 1500, 1800.
4. To construct a triangle with three given measurements.

IMPORTANT POINTS AND CONCEPTS PERTAINING TO THE CHAPTER:
1. Radius and tangent of a circle perpendicular to each other at a point of contact.
2. Sum of angles of a quadrilateral is 360 degree.
3. Length of tangents drawn from external point is equal in length.
4. Sum of angles of a triangle is 1800.
5. Concept of similar triangles( corresponding angles are equal).
6. Always join the denominator in the end point of base of given triangle.

CONSTRUCTIONS TO BE DONE IN THIS CHAPTER:
1. To divide a line segment in a given ratio.
2. To construct a triangle similar to a given triangle as per given scale factor which may
be less than or may be greater than 1.
3. To construct tangent at a point on a given circle.
4. To construct the pair of tangents from an external point to a circle.

IMPORTANT POINTS OF CONSTRUCTION OF TANGENTS
1. Construction of tangents to a circle from a point outside it.
2. Construction of tangents to a circle from a point on it.
3. Construction of pair of tangents to a circle which are inclined to each other