Students can go through AP 8th Class Maths Notes Chapter 4 Practical Geometry to understand and remember the concepts easily.
Class 8 Maths Chapter 4 Notes Practical Geometry
→ Five measurements can determine a quadrilateral uniquely.
→ A quadrilateral can be constructed uniquely if the lengths of its four sides and a diagonal is given.
→ A quadrilateral can be constructed uniquely if its two diagonals and three sides are known.
→ A quadrilateral can be constructed uniquely if its two adjacent sides and three angles are known.
→ A quadrilateral can be constructed uniquely if its three sides and two included angles are given.
→ To construct a triangle we need 3 measurements but for construction of a unique quadrilateral we need 5 measurements.
Sides, Angles, Diagonals etc., are to be given in 5 individual measurements.
Case – I : When the lengths of four sides and diagonals are given, then the procedure for construction is as follows :
Steps :
- draw a rough diagram and iable it as given/asked.
- show the given measurements in the rough diagram.
- draw a side and mark it.
- now draw a triangle.
- then to locate fourth vertex, draw an arc for diagonal and using the remaining side.
- the intersection point of these two arcs will be the fourth vertex of the required quadrilateral.
- Then by joining all these we get required quadrilateral.