Polygon – Interior and Exterior & Central Angles Interior angle of a regular polygon A regular polygon has all the interior angles same in measure, and all interior angles of polygon formed by each pair of adjacent sides. When a polygon has n sides n vertices and n interior angles. Interior angle = 1800 – Central angle […]
Read More →Theorem – The line segment joining the mid-points of two sides of a triangle is parallel to the third side. Given: A triangle △ABC, in which D and E are mid points of sides AB and AC respectively. DE is joined. To prove: Line joining the mid points D and E (DE) is parallel to the third line […]
Read More →Axis of Symmetry – Symmetrical Figures Definition – Axis of Symmetry: A line is drawn from the middle of the figure that acts like a mirror is known as Axis of Symmetry or Linear Symmetry. The line divides the figure into two symmetrical parts, then figure on one side is the mirror image of the figure on […]
Read More →Theorem – Alternate Interior Angles are Equal If a transversal intersects two parallel lines, then each pair of alternate interior angles are equal. Given: Two parallel Lines AB and CD, and PS be transversal intersecting AB at Q and CD at R. To Prove: Each pair of alternate interior angles are equal. i.e. ∠BQR = ∠CRQ and ∠AQR = ∠QRD […]
Read More →SSS, SAS, ASA, AAS and RHS – Congruence of Triangles In geometry we see that, if two line segments are are same in length, they are congruent, and if two angles are same in measure they are also congruent,.Simply, we can say congruent means an object and its mirror image. Congruence Triangles A triangle is a polygon with […]
Read More →Perpendicular Lines Definition: Perpendicular Lines A line intersect another line and the angle between them is a right angle or 900 then the lines are said to be “Perpendicular.” If a line AB perpendicular to CD, we write asAB ⊥ CD. Perpendicular denoted by “⊥” If one of the angles formed by the intersection of two lines or line segments […]
Read More →Pie Graph or Pie Chart – Definition and Examples Pie Graph (Pie Chart) Definition: A “pie graph or (pie chart)” is a circular chart divided into sectors, each sector represents a proportionate part of a whole. A pie graph is used to compare parts of a whole. The circle represent the whole. Sector: In a pie graph, the […]
Read More →Similar Figures – Definition and Examples Definition: If two figures have the same shape, then they are called ” Similar Figures”. The ratio of length of their corresponding sides are equal, and their corresponding angles are equal. In below triangles ABC and PQR corresponding angles are equal so, […]
Read More →The perpendicular from the center of a circle to a chord bisects the chord. Given: A circle with center O, AB is chord of a circle and OC perpendicular from the center O to the chord AB. i.e. OC ⊥ AB therefore ∠OCA and ∠OCB, Both angles are 900. To prove: AC = CB Construction: join OA and OB. Proof: In △OCA and △ OCB ∠OCA = ∠OCB […]
Read More →If a transversal intersect two parallel lines, then each pair of interior angles on the Same side of the transversal are Supplementary. Given: Two parallel Lines AB and CD, and PS be transversal intersecting AB at Q and CD at R. To Prove: Sum of interior angles on the Same side of the transversal is Supplementary. […]
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