Exercise 8.2 Class 10 Math Solutions – Arc, Chord & Central Angle Theorems, Punjab Board

Solved Exercise 8.2 for Class 10 Mathematics, Punjab Board. Comprehensive step-by-step notes covering Theorems 6 to 9 on congruent arcs, equal chords, and central angles in single and congruent circles with complete geometric proofs.

This page provides complete solved solutions for Exercise 8.2 from Unit 8: Chords and Arcs of a Circle, Class 10 Mathematics, Punjab Board (PCTB). It covers formal Euclidean proofs for Theorems 6 through 9: proving that congruent arcs determine equal chords and vice versa, and that equal chords subtend equal angles at the circle's centre and vice versa. Fully worked proofs and exercise applications are provided for Matric Part 2 students.
Advertisement

Exercise Overview

Exercise 8.2 in Unit 8: Chords and Arcs of a Circle of Class 10 Punjab Board Mathematics focuses on the direct and converse relationships linking circular arcs, chords, and central angles. This exercise delivers rigorous mathematical proofs establishing how arc congruence dictates linear chord equality and angular central symmetry.

The exercise systematically covers four major Euclidean theorems: Theorem 6 (congruent arcs yield equal chords), Theorem 7 (equal chords subtend congruent arcs), Theorem 8 (equal chords subtend equal central angles), and Theorem 9 (equal central angles are subtended by equal chords). By constructing triangles with radii and applying SAS and SSS triangle congruence postulates, students develop a logical framework for deductive geometric reasoning across both single circles and pairs of congruent circles.

In Punjab Board examinations across Lahore, Faisalabad, Rawalpindi, Gujranwala, Multan, Sargodha, Bahawalpur, and DG Khan, Theorems 6 through 9 and their rider problems are prominent questions in the compulsory geometry theorem portion of Section C. Mastering these step-by-step proofs equipped with exact diagrams and valid axiomatic justifications guarantees full marks in board exams.

FAQs

Are these Exercise 8.2 solutions according to the Punjab Board syllabus?
Yes. These solutions follow the Punjab Curriculum and Textbook Board (PCTB) syllabus for Class 10 Mathematics, covering all Unit 8 Exercise 8.2 circle theorems for the 2026-2027 session.
What does Theorem 6 state regarding congruent arcs in a circle?
Theorem 6 states that if two arcs of a circle (or of congruent circles) are congruent, then the corresponding chords joining their endpoints are equal in length.
What is the converse theorem to Theorem 6 in Unit 8?
Theorem 7 is the converse: if two chords of a circle (or congruent circles) are congruent, then their corresponding minor and major arcs are congruent.
How are equal chords related to angles subtended at the centre?
Theorem 8 proves that equal chords of a circle (or of congruent circles) subtend equal central angles at the centre.
What is proven in Theorem 9 regarding central angles?
Theorem 9 proves the converse: if the angles subtended by two chords at the centre of a circle are equal, then the chords themselves are equal in length.
Can these theorems be applied to two separate congruent circles?
Yes, all four theorems (6, 7, 8, and 9) apply identically to chords, arcs, and central angles within a single circle or across two separate congruent circles.
Are all theorem proofs structured with Given, To Prove, and Reason tables?
Yes, every theorem in Exercise 8.2 is solved with standard geometric proof sections including Given, To Prove, Construction, and Statement-Reason tables.
Can students read these Exercise 8.2 solutions online?
Yes, the complete solved PDF notes for Exercise 8.2 are embedded to read online directly on MaryamNotes.pk with no compulsory download.
Are these Exercise 8.2 solutions free for students?
Yes, all Exercise 8.2 solutions on MaryamNotes.pk are 100% free to read online for all Class 10 students across all Punjab boards.