Geometry

Lengths in Polygons on the Plane

Cointerior Angles

Alternate Angles

Angles and Parallel Lines

Identifying Parallel Lines

Angles in Triangles Revision

Geometrical Calculations

Proofs with Triangles

Proofs with Quadrilaterals

Proofs Using Congruent Triangles

Applications of Circle Geometry

Proofs and Theorems involving Circles

Medians and Midpoints in a Triangle

Proofs of corresponding, alternate and cointerior angles

Class IX

Geometrical Calculations

Interactive practice questions

From the diagram:

a

Find $y$y.

b

Find $x$x. giving reasons

Easy

2min

Find the size of angle $x$x, giving reasons.

Note: the diagram is not to scale.

Easy

7min

Find the size of angle $x$x, giving reasons.

Easy

6min

Find the size of angle $x$x, giving reasons.

Easy

5min

Outcomes

9.G.Q.1

The diagonal divides a parallelogram into two congruent triangles. In a parallelogram opposite sides are equal and conversely. In a parallelogram opposite angles are equal and conversely. A quadrilateral is a parallelogram if a pair of its opposite sides is parallel and equal. In a parallelogram, the diagonals bisect each other and conversely.

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