Triangles Practice Questions
Class 10 · Mathematics · 1584 free MCQs with instant results and detailed explanations.
1584
Total
566
Easy
756
Medium
262
Hard
Start Practicing Triangles
Take a timed quiz or customize your practice session
Topics in Triangles
Pythagoras Theorem
374
Similarity of Triangles
486
Areas of Similar Triangles
360
Basic Proportionality Theorem
364
Sample Questions from Triangles
Here are 10 sample questions. Start a quiz to get randomized questions with scoring.
Q1
Easy
If two triangles are similar, which of the following is true about their corresponding angles?
A.
They are equal.
B.
They are supplementary.
C.
They are complementary.
D.
They are unequal.
Show Answer & Explanation
Correct Answer: A
In similar triangles, corresponding angles are equal, which is a fundamental property of similarity.
Q2
Easy
In triangle XYZ, if angle X = 30°, angle Y = 60°, and angle Z = 90°, which triangle is similar to it?
A.
Triangle PQR with angles 30°, 60°, 90°
B.
Triangle ABC with angles 45°, 45°, 90°
C.
Triangle DEF with angles 60°, 30°, 90°
D.
Triangle GHI with angles 30°, 90°, 60°
Show Answer & Explanation
Correct Answer: A
Triangles are similar if their corresponding angles are equal. Triangle PQR has the same angles as triangle XYZ.
Q3
Easy
If triangle ABC is similar to triangle DEF and the length of side BC is 5 cm while side EF is 10 cm, what is the ratio of the lengths of the sides?
A.
1:1
B.
1:2
C.
2:1
D.
3:1
Show Answer & Explanation
Correct Answer: B
The ratio of corresponding side lengths of similar triangles is constant. Here, BC to EF gives a ratio of 1:2.
Q4
Medium
In triangle ABC, if angle A = angle D and angle B = angle E, which of the following is true?
A.
Triangle ABC is similar to triangle DEF.
B.
Triangle ABC is congruent to triangle DEF.
C.
Triangle ABC is larger than triangle DEF.
D.
Triangle ABC is equilateral.
Show Answer & Explanation
Correct Answer: A
If two angles of one triangle are equal to two angles of another triangle, the two triangles are similar by AA criterion.
Q5
Medium
If two triangles are similar, and the lengths of the corresponding sides of the triangles are in the ratio 3:5, what is the ratio of their areas?
A.
9:25
B.
15:25
C.
3:5
D.
1:1
Show Answer & Explanation
Correct Answer: A
The areas of similar triangles are in the ratio of the squares of the lengths of their corresponding sides.
Q6
Medium
In triangle PQR, if PQ = 6 cm, QR = 8 cm, and angle PQR = 50°, what is the length of side PR if triangle PST is similar to triangle PQR with PS = 3 cm?
A.
4 cm
B.
5 cm
C.
6 cm
D.
8 cm
Show Answer & Explanation
Correct Answer: A
Using the properties of similar triangles, the sides are in proportion, hence PR = (PS * QR) / PQ.
Q7
Medium
In triangles ABC and DEF, if AB/DE = 2/3 and AC/DF = 2/3, what can be concluded about the triangles?
A.
The triangles are similar.
B.
The triangles are congruent.
C.
The triangles are not similar.
D.
They can be right-angled.
Show Answer & Explanation
Correct Answer: A
By the criterion of similarity (SSS), if the ratios of all three sides are equal, the triangles are similar.
Q8
Hard
In triangle ABC, if AB = 4 cm, BC = 6 cm, and AC = 8 cm, and triangle DEF is similar to triangle ABC with DE = 8 cm, what is the length of DF?
A.
12 cm
B.
10 cm
C.
16 cm
D.
14 cm
Show Answer & Explanation
Correct Answer: B
Using the properties of similar triangles, the sides are proportional. DE/AB = DF/BC. Thus, DF is 10 cm.
Q9
Hard
If two triangles are similar and the ratio of their areas is 16:25, what is the ratio of their corresponding sides?
A.
4:5
B.
3:5
C.
16:25
D.
8:5
Show Answer & Explanation
Correct Answer: A
The ratio of the areas of similar triangles is the square of the ratio of their corresponding sides. Thus, √(16/25) = 4/5.
Q10
Hard
In triangles ABC and DEF, if angle A = angle D and angle B = angle E, which of the following statements is true?
A.
ABC is similar to DEF.
B.
DEF is larger than ABC.
C.
The triangles are congruent.
D.
Angle C = Angle F.
Show Answer & Explanation
Correct Answer: A
By AA similarity criterion, if two angles of one triangle are equal to two angles of another triangle, the triangles are similar.
Showing 10 of 1584 questions. Start a quiz to practice all questions with scoring and timer.
Practice All 1584 Questions →More Mathematics Chapters
Other Class 10 Subjects
Triangles — Class 10 Mathematics Practice Questions Online
This page contains 1584 practice MCQs for the chapter Triangles in Class 10 Mathematics. The questions are organized by difficulty — 566 easy, 756 medium, 262 hard — so you can choose the right level for your preparation.
Every question includes a detailed explanation to help you understand the concept, not just memorize answers. Take a timed quiz to simulate exam conditions, or practice at your own pace with no time limit. This chapter covers 4 topics, giving you comprehensive coverage of the entire chapter.