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# Summary

Geometry | Chapter 4 | 8th Maths : Summary

SUMMARY

Congruent figures are exactly the same in shape and size.

Similar figures have the same shape but different sizes.

In a right angled triangle, the square on the hypotenuse is equal to the sum of the squares on the other two sides. This is known as Pythagoras theorem.

The three medians of any triangle are concurrent. The point of concurrence of the three medians in a triangle is called its Centroid, denoted by the letter G.

The three altitudes of any triangle are concurrent. The point of concurrence of the three altitudes of a triangle is called as its Orthocentre, denoted by the letter H.

The three perpendicular bisectors of the sides of any triangle are concurrent. The point of concurrence of the three perpendicular bisectors of a triangle is called as its Circumcentre, denoted by the letter S.

The three angle bisectors of any triangle are concurrent. The point of concurrence of the three angle bisectors of a triangle is called as its Incentre, denoted by the letter I.

A trapezium is a quadrilateral in which a pair of opposite sides are parallel.

A parallelogram is a quadrilateral in which the opposite sides are parallel.

Rhombus is a parallelogram in which all its sides are congruent.

Rectangle is a parallelogram whose all its angles are right angles.

Square is a parallelogram in which all its sides and angles are equal.

ICT CORNER

Expected Outcome Step-1 Open the Browser type the URL Link given below (or) Scan the QR Code. GeoGebra work book named “GEOMETRY” will open. Click on the worksheet named “Parallelogram”.

Step-2 In the given worksheet you can move the sliders Base, Height and the angle. Check for what value(s) the parallelogram becomes rectangle and square. Study the properties. Geometry:

https://www.geogebra.org/m/fqxbd7rz#chapter/409576 or Scan the QR Code.

ICT CORNER

Expected Outcome Step-1 Open the Browser type the URL Link given below (or) Scan the QR Code. GeoGebra work sheet named “8th Standard III term” will open. Select the work sheet named “Rectangle Construction”.

Step-2 Move the sliders on left side to change the length and breadth of the rectangle. Drag the slider step by step on right side to see the steps for construction. Geometry:

https://www.geogebra.org/m/xmm5kj9r or Scan the QR Code.

Tags : Geometry | Chapter 5 | 8th Maths , 8th Maths : Chapter 5 : Geometry
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8th Maths : Chapter 5 : Geometry : Summary | Geometry | Chapter 5 | 8th Maths