NCERT Triangles MCQs – Area Theorem and Similarity Criteria
CBSE Class 10 Mathematics – Chapter 6: Triangles
Title: NCERT Triangles MCQs – Area Theorem and Similarity Criteria
Prepared for: CBSE Board Examinations (As per Latest NCERT Curriculum)
Q1. If two triangles are similar, the ratio of their areas is equal to:
Correct Answer: B. Square of ratio of corresponding sides
According to Area Theorem, Area ratio = (Side ratio)².
Q2. If ratio of areas of two similar triangles is 16:25, the ratio of corresponding sides is:
Correct Answer: A. 4:5
Side ratio = √(16/25) = 4/5.
Q3. If two triangles have equal corresponding angles, they are similar by:
Correct Answer: C. AAA
When all corresponding angles are equal, triangles are similar (AAA criterion).
Q4. If sides of two triangles are proportional, similarity criterion used is:
Correct Answer: B. SSS
SSS similarity: All three sides proportional.
Q5. If ratio of corresponding sides is 3:5, ratio of areas is:
Correct Answer: B. 9:25
Area ratio = (3/5)² = 9/25.
Q6. If two sides proportional and included angle equal, criterion is:
Correct Answer: A
SAS similarity criterion.
Q7. Ratio of areas 49:64, ratio of sides?
Correct Answer: A
√(49/64)=7/8.
Q8. If ΔABC ~ ΔDEF, then AB corresponds to:
Correct Answer: A
Order indicates correspondence.
Q9. Ratio of perimeters of similar triangles equals:
Correct Answer: B
Perimeter depends on linear measure.
Q10. If area ratio is 1:4, side ratio is:
Correct Answer: A
√(1/4)=1/2.
Q11. Converse of Basic Proportionality Theorem states line is:
Correct Answer: B
If sides divided proportionally, line is parallel.
Q12. If two triangles are congruent, they are always:
Correct Answer: A
Congruent triangles have same shape & size → similar.
Q13. In similar triangles, altitudes are:
Correct Answer: B
All linear measures proportional.
Q14. If scale factor is 5, area scale factor is:
Correct Answer: C
Area factor = 5² = 25.
Q15. AAA similarity implies triangles have same:
Correct Answer: A
Angles same → shape same, size may differ.
Q16. If sides 6,8,10 and 9,12,15 triangles are:
Correct Answer: A
Each side multiplied by 1.5 → proportional.
Q17. Ratio of medians of similar triangles equals:
Correct Answer: B
Medians are linear measures.
Q18. If area ratio is 36:49, side ratio:
Correct Answer: A
√(36/49)=6/7.
Q19. Similar triangles always have equal:
Correct Answer: A
Corresponding angles are equal.
Q20. If corresponding sides ratio is k, area ratio equals:
Correct Answer: B
Area theorem → area proportional to square of sides.
