Class 9 Maths Chapter 7 Triangles MCQs

You can access Class 9 Maths Chapter 7: Triangles MCQs with answers online, designed as per the latest CBSE (2025-26) exam pattern and NCERT guidelines. Practicing these MCQs helps students strengthen their preparation and improve exam readiness. Each question is accompanied by a clear explanation for better concept clarity. Explore chapter-wise MCQs and important questions for Class 9 Maths at Infinity Learn.

MCQs on Class 9 Maths Chapter 7 Triangles

Q. Which of the following is not a type of triangle based on sides?

A) Equilateral

B) Isosceles

C) Scalene

D) Right

Solution: D) Right

Q. In an equilateral triangle, each angle measures:

A) 45°

B) 60°

C) 90°

D) 180°

Solution: B) 60°

Q. The sum of all angles of a triangle is:

A) 90°

B) 180°

C) 270°

D) 360°

Solution: B) 180°

Q. In an isosceles triangle, the angles opposite to equal sides are:

A) Right angles

B) Acute angles

C) Obtuse angles

D) Equal angles

Solution: D) Equal angles

Q. Which theorem states that the sum of all angles of a triangle is 180°?

A) Pythagoras Theorem

B) Angle Sum Property

C) Isosceles Triangle Theorem

D) Midpoint Theorem

Solution: B) Angle Sum Property

Q. The side opposite to the right angle in a right-angled triangle is called:

A) Hypotenuse

B) Adjacent side

C) Opposite side

D) Base

Solution: A) Hypotenuse

Q. Which of the following cannot be the angles of a triangle?

A) 30°, 60°, 90°

B) 50°, 60°, 70°

C) 40°, 50°, 100°

D) 45°, 45°, 90°

Solution: C) 40°, 50°, 100°

Q. The point where all medians of a triangle meet is called:

A) Orthocenter

B) Centroid

C) Incenter

D) Circumcenter

Solution: B) Centroid

Q. The ratio of the areas of two similar triangles is equal to the ratio of the squares of their corresponding:

A) Perimeters

B) Altitudes

C) Medians

D) Angles

Solution: B) Altitudes

Q. The ratio of the corresponding sides of two similar triangles is known as:

A) Congruence

B) Proportionality

C) Similarity

D) Perpendicularity

Solution: C) Similarity

Q. In a right-angled triangle, the side opposite to the angle of 30° is:

A) Hypotenuse

B) Base

C) Perpendicular

D) None of these

Solution: C) Perpendicular

More resources for class 9

• NCERT Solutions for Class 9 Maths
• NCERT Solutions for Class 9 Science
• NCERT Solutions for Class 9 Social Science

Q. The angles of a triangle are in the ratio 2:3:5. The largest angle is:

A) 30°

B) 40°

C) 50°

D) 60°

Solution: D) 60°

Q. Which of the following pairs of triangles is always similar?

A) Equilateral and Isosceles

B) Scalene and Equilateral

C) Equilateral and Scalene

D) Isosceles and Scalene

Solution: B) Scalene and Equilateral

Q. The bisectors of the angles of a triangle intersect at a point called:

A) Centroid

B) Incenter

C) Orthocenter

D) Circumcenter

Solution: B) Incenter

Q. If the sides of a triangle are in the ratio 3:4:5, then the triangle is:

A) Equilateral

B) Isosceles

C) Scalene

D) Right-angled

Solution: D) Right-angled

Q. The perimeter of an equilateral triangle with each side measuring 6 cm is:

A) 12 cm

B) 18 cm

C) 24 cm

D) 36 cm

Solution: B) 18 cm

Q. Which theorem is used to prove that two triangles are similar?

A) Pythagoras Theorem

B) Thales Theorem

C) AA Similarity Theorem

D) SAS Similarity Theorem

Solution: C) AA Similarity Theorem

Q. The ratio of the corresponding altitudes of two similar triangles is equal to the ratio of their:

A) Perimeters

B) Areas

C) Corresponding sides

D) Angles

Solution: C) Corresponding sides

Q. In an isosceles triangle, the angle opposite to the base is called:

A) Right angle

B) Acute angle

C) Obtuse angle

D) Vertex angle

Solution: D) Vertex angle

Q. The line segment joining the midpoints of two sides of a triangle is called:

A) Median

B) Perpendicular bisector

C) Altitude

D) Angle bisector

Solution: A) Median