The straight lines which are parallel to the same straight line are parallel...
Theorem: If a straight line intersects another two straight lines and if the corresponding angles are equal to each other. General enunciation: If a straight line intersects another two straight lines...
View ArticleIf three sides of a triangle are respectively equal to the corresponding...
General enunciation: If three sides of a triangle are respectively equal to the corresponding three sides of another triangle, then the triangle are congruent. Particular enunciation: Let, in ∆ABC...
View ArticleIf two sides of a triangle are equal, then the angles opposite the equal...
General enunciation: If two triangles have two sides of the one equal to two sides of the other, each to each, the angles included by those sides are also equal then the triangles are equal in all...
View ArticleSolution of exercise 9.2(Triangle)| Class seven
Problem-9: In the triangle ABC, AB>AC and the bisectors of the ∠B and ∠C intersect at the point P. Prove that PB>PC. Particular enunciation: Given that, in the triangle ABC, AB>AC and the...
View ArticleIf two angles of triangles are equal, then the sides opposite to the equal...
If two angles of triangles are equal, then the sides opposite to the equal angles are equal. Particular enunciation: Let ABC be a triangle in which the ∠ACB = the ∠ABC. We have to prove that AB =AC....
View ArticleIf two triangles have the three sides of the one equal to the three sides of...
If two triangles have the three sides of the one equal to the three sides of the other, each to each, then they are equal in all respects. Particular enunciation: In the ∆ABC and ∆DEF, AB = DE, AC =...
View ArticleExercise 10.1|Class seven| Congruence| Part – 1
Problem – 1: In the figure, CD is the perpendicular bisector of AB, Prove that ∆ADC ≅ ∆BDC. Solution: Particular enunciation: Given that, in the figure, CD is the perpendicular bisector of AB. i.e., AD...
View ArticleSolution exercise 9.1| Class seven| Geometry
Problem-1: In the figure, ∆ABC is a triangle in which ∠ABC = 900, ∠BAC =480 and BD is perpendicular to AC. Find the remaining angles. Solution: Let remaining angles ∠ABD = x, ∠DBC = y and ∠BCD = z....
View ArticleExercise 10.1|Class seven| Congruence| Part – 2
Problem – 5: In the figure, AD = AE, BD = CE and ∠AEC = ∠ADB. Prove that AB = AC. Particular enunciation: In the figure, AD = AE, BD = CE and ∠AEC = ∠ADB. We have to prove that AB = AC. Proof: In ∆ACE...
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