Mathematics
Triangles
त्रिभुज
This Class 9 Mathematics chapter develops a clear understanding of triangles and the principles used to compare and prove their properties. Students learn about congruence, including the SSS, SAS, ASA, and RHS criteria, and apply these rules to establish equal sides and angles. The chapter also explores relationships between sides and opposite angles, helping learners solve geometric problems through logical reasoning, diagrams, and step-by-step proofs.
1Congruent triangles
सर्वांगसम त्रिभुज
In this Class 9 Mathematics topic from the chapter “Triangles,” students learn when two triangles are exactly equal in shape and size. They explore the meaning of congruence, understand corresponding sides and angles, and apply criteria such as SSS, SAS, ASA and RHS to establish whether triangles are congruent. The topic also develops clear geometric reasoning through diagrams, statements and proofs, helping students solve problems involving equal parts of triangles.
0 questionsSAS congruence
भुजा-कोण-भुजा सर्वांगसमता
In this Class 9 Mathematics topic from the chapter Triangles, students learn the SAS (Side–Angle–Side) congruence criterion. They understand that two triangles are congruent when two corresponding sides and the angle included between them are equal. The topic develops skills for identifying corresponding parts, matching vertices correctly, presenting clear geometric proofs, and using SAS to establish that other corresponding sides and angles are equal in congruent triangles.
0 questionsSSS congruence
भुजा-भुजा-भुजा (SSS) सर्वांगसमता
In Class 9 Mathematics, this topic explains the SSS (Side–Side–Side) congruence criterion for triangles. Students learn that two triangles are congruent when their three corresponding sides are equal in length, and how to match corresponding vertices and sides before applying the criterion. They practise identifying given measurements, writing a valid congruence statement, and using SSS to justify that corresponding angles or other parts are equal. The topic develops careful geometric reasoning within the chapter on Triangles.
0 questionsASA congruence
ASA सर्वांगसमता नियम
In this Class 9 Mathematics topic from the chapter Triangles, students learn the ASA (Angle-Side-Angle) congruence criterion. They understand that two triangles are congruent when two corresponding angles and the side included between those angles are equal. The topic develops skills for identifying corresponding parts, matching vertices in the correct order, writing a valid congruence statement, and using ASA to justify geometric results and solve problems involving triangles.
0 questionsRHS congruence
RHS सर्वांगसमता प्रमेय
RHS (Right angle–Hypotenuse–Side) congruence is a method for proving that two right-angled triangles are congruent. In this Class 9 Mathematics topic from the chapter Triangles, students learn that equality of the right angle, hypotenuse, and one corresponding side is sufficient to establish congruence. They practise identifying corresponding parts, applying the RHS criterion in geometric proofs, and using congruent triangles to determine unknown sides or angles and justify relationships in diagrams.
0 questionsAAS congruence
AAS सर्वांगसमता
In Class 9 Mathematics, this topic explores the AAS (Angle–Angle–Side) congruence criterion within the chapter on Triangles. Students learn how two triangles can be proved congruent when two corresponding angles and a corresponding non-included side are equal. They practise identifying matching parts, writing clear geometric proofs, using angle relationships, and applying the criterion to determine equal sides or angles in diagrams. The topic strengthens logical reasoning and accurate use of congruence notation.
0 questionsIsosceles triangle properties
समद्विबाहु त्रिभुज के गुणधर्म
In this Class 9 Mathematics topic from the chapter Triangles, students study the defining properties of an isosceles triangle: two equal sides and the equal angles opposite them. They learn how to identify the base and base angles, use the theorem that equal sides subtend equal angles, and understand its converse. The topic also connects these ideas with proofs, angle calculations, constructions, and solving geometric problems involving symmetry and congruent triangles.
0 questions