Looking for authentic SEBA Class 10 Mathematics Chapter R-5 (Revision 5) solutions for the 2026–27 academic year? Access step-by-step solved textual exercise questions tailored to help you revise key concepts and score high in your HSLC board exams.
Exercise : R-5
Question 1
Two triangles are congruent if:
(a) Their areas are equal
(b) Their shapes are the same but sizes may differ
(c) All corresponding sides and angles are equal
(d) Only their perimeters are equal
Solution:
By definition, congruent triangles have identical shape and size, which means all their corresponding sides and angles are equal.
Ans: (c) All corresponding sides and angles are equal
Question 2
Which of the following is a valid congruency rule?
(a) AAA
(b) SSA
(c) SAS
(d) ASS
Solution:
Out of the given options, SAS (Side-Angle-Side) is a standard valid criteria for congruence of triangles.
Ans: (c) SAS
Question 3
If two sides and the included angle of one triangle are equal to two sides and the included angle of another triangle, the triangles are congruent by:
(a) ASA
(b) SAS
(c) AAS
(d) RHS
Solution:
Two Sides (S) and the included Angle (A) directly correspond to the Side-Angle-Side (SAS) congruence rule.
Ans: (b) SAS
Question 4
Which congruence rule is used when two angles and the included side are equal?
(a) AAS
(b) ASA
(c) SAS
(d) RHS
Solution:
Two Angles (A) and the included Side (S) correspond to the Angle-Side-Angle (ASA) congruence rule.
Ans: (b) ASA
Question 5
Right-angled triangles are congruent by RHS if they have equal:
(a) Hypotenuse and one acute angle
(b) Two acute angles
(c) Hypotenuse and one corresponding side
(d) All sides
Solution:
RHS stands for Right angle, Hypotenuse, and Side. Therefore, the hypotenuse and one corresponding side must be equal.
Ans: (c) Hypotenuse and one corresponding side
Question 6
AAS congruence rule means:
(a) Two angles and a side not included between them
(b) Two sides and an angle
(c) Three angles
(d) One side and one angle
Solution:
AAS stands for Angle-Angle-Side, which refers to two angles and a non-included side.
Ans: (a) Two angles and a side not included between them
Question 7
If ∠A = ∠D, ∠B = ∠E and AB = DE, then △ABC ≅ △DEF by:
(a) SAS
(b) AAS
(c) ASA
(d) RHS
Solution:
Here, two angles (∠A, ∠B) and the included side (AB) of △ABC are equal to two angles (∠D, ∠E) and the included side (DE) of △DEF.
∴ By ASA rule, △ABC ≅ △DEF.
Ans: (c) ASA
Question 8
In △ABC and △PQR, if AB = PQ, BC = QR, and AC = PR, the triangles are congruent by:
(a) ASA
(b) SSS
(c) SAS
(d) RHS
Solution:
All three corresponding sides of both triangles are equal (S = S = S).
∴ By SSS rule, the triangles are congruent.
Ans: (b) SSS
Question 9
The symbol ‘≅’ represents
(a) Similarity
(b) Congruency
(c) Parallel
(d) Perpendicular
Solution:
The symbol ‘≅’ is universally used in geometry to represent congruency.
Ans: (b) Congruency
Question 10
Congruent triangles have:
(a) Equal corresponding sides
(b) Equal corresponding angles
(c) Same shape and same size
(d) All of these
Solution:
Congruent triangles satisfy all of the given properties: equal corresponding sides, equal corresponding angles, and identical shape and size.
Ans: (d) All of these
📐 Updated Solutions Notice: This post provides step-by-step SEBA Class 10 Mathematics Chapter R-5 (Revision 5) Textual Exercise Solutions updated for the 2026–27 academic session. All calculations and explanations follow the latest revised Assam Board (SEBA) textbook syllabus.
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