triangle geometry - centres of triangle, congruence and similarity of triangles - Question Bank

1. The orthocenter, centroid, and circumcenter of a non-equilateral triangle are always:
A) Coincident
B) Collinear
C) Forming an equilateral triangle
D) Forming a right-angled triangle
2. If ∆ABC ~ ∆DEF, and the ratio of similarity is 1:2, then the ratio of the area of ∆ABC to the area of ∆DEF is:
A) 1:2
B) 1:4
C) 2:1
D) 4:1
3. Which theorem states that if a line is drawn parallel to one side of a triangle intersecting the other two sides in distinct points, then the other two sides are divided in the same ratio?
A) Pythagorean Theorem
B) Basic Proportionality Theorem (Thales' Theorem)
C) Angle Bisector Theorem
D) Apollonius' Theorem
4. The point of concurrency of the angle bisectors is called the:
A) Circumcenter
B) Orthocenter
C) Centroid
D) Incenter
5. If two triangles are similar, then the ratio of the square of their corresponding altitudes is equal to the ratio of their:
A) Perimeters
B) Areas
C) Medians
D) Sides
6. In triangle ABC, the angle bisector of ∠A, the median to BC, and the altitude to BC are concurrent if the triangle is:
A) Scalene
B) Isosceles
C) Right-angled
D) Obtuse
7. If the ratio of corresponding altitudes of two similar triangles is 3:5, then the ratio of their areas is:
A) 3:5
B) 9:25
C) 27:125
D) 1:1
8. The center of the circle passing through the midpoints of the sides of a triangle is the:
A) Centroid
B) Orthocenter
C) Circumcenter of the medial triangle
D) Incenter
9. In ∆ABC, if ∠A = 30°, ∠B = 60°, and ∠C = 90°, and ∆DEF has ∠D = 30°, ∠E = 60°, ∠F = 90°, then the triangles are:
A) Congruent
B) Similar
C) Neither congruent nor similar
D) Cannot be determined
10. If ∆ABC ≅ ∆DEF, then the ratio of their perimeters is:
A) 1:1
B) 1:2
C) 2:1
D) Depends on the sides
11. Which of the following is true for any triangle?
A) The centroid always lies inside the triangle.
B) The orthocenter always lies outside the triangle.
C) The incenter always lies on a side of the triangle.
D) The circumcenter is always at a vertex.
12. Two triangles are similar if their corresponding sides are in the same ratio. This is the property of:
A) Congruence
B) Similarity
C) Equilateral triangles
D) Isosceles triangles
13. If ∆ABC is equilateral, which of the following points coincide?
A) Centroid and Orthocenter only
B) Circumcenter and Incenter only
C) All four centers (Centroid, Orthocenter, Circumcenter, Incenter)
D) Centroid and Circumcenter only
14. In ∆ABC, if AB = AC and AD is the altitude to BC, then D is the:
A) Centroid
B) Orthocenter
C) Midpoint of BC
D) Incenter
15. If two triangles have the same area, are they necessarily congruent?
A) Yes
B) No
C) Only if they are equilateral
D) Only if they are right-angled
16. In an isosceles triangle, the altitude from the vertex angle is also the:
A) Median and angle bisector
B) Perpendicular bisector of the base
C) Only the median
D) Only the angle bisector
17. The locus of points equidistant from two intersecting lines is:
A) A perpendicular line
B) A parallel line
C) The angle bisector
D) The median
18. If ∆ABC ~ ∆XYZ, and AB = 2, BC = 3, AC = 4, and XY = 4, then YZ is:
A) 4
B) 5
C) 6
D) 8
19. Which congruence criterion requires two angles and a non-included side to be equal?
A) SSS
B) SAS
C) ASA
D) AAS
20. If ∆ABC ≅ ∆DEF, then ∠B = ∠?
A) ∠D
B) ∠E
C) ∠F
D) ∠A
21. In ∆ABC, if ∠A = 90°, where is the orthocenter located?
A) At B
B) At C
C) At A
D) At the midpoint of BC
22. Which center of a triangle is equidistant from the vertices?
A) Incenter
B) Centroid
C) Circumcenter
D) Orthocenter
23. The point where the perpendicular bisectors of the sides of a triangle meet is called the:
A) Incenter
B) Centroid
C) Circumcenter
D) Orthocenter
24. In ∆ABC, AD is the median to side BC. The centroid G divides AD in the ratio:
A) 1:2
B) 2:1
C) 1:1
D) 3:1
25. The ratio of the areas of two similar triangles is equal to the square of the ratio of their:
A) Corresponding sides
B) Corresponding medians
C) Corresponding altitudes
D) All of the above
26. If two triangles are similar, the ratio of their corresponding sides is equal to the ratio of their:
A) Areas
B) Perimeters
C) Medians
D) Altitudes
27. The AAA similarity rule states that two triangles are similar if:
A) Two angles and the included side of one triangle are proportional to the corresponding angles and side of the other triangle.
B) Two sides of one triangle are proportional to the corresponding sides of the other triangle, and the included angles are equal.
C) All three sides of one triangle are proportional to the corresponding sides of the other triangle.
D) All three angles of one triangle are equal to the corresponding angles of the other triangle.
28. The SAS similarity rule states that two triangles are similar if:
A) Two angles and the included side of one triangle are proportional to the corresponding angles and side of the other triangle.
B) Two sides of one triangle are proportional to the corresponding sides of the other triangle, and the included angles are equal.
C) All three sides of one triangle are proportional to the corresponding sides of the other triangle.
D) All three angles of one triangle are equal to the corresponding angles of the other triangle.
29. The SSS similarity rule states that two triangles are similar if:
A) Two angles and the included side of one triangle are proportional to the corresponding angles and side of the other triangle.
B) Two sides and the included angle of one triangle are proportional to the corresponding sides and angle of the other triangle.
C) All three sides of one triangle are proportional to the corresponding sides of the other triangle.
D) All three angles of one triangle are equal to the corresponding angles of the other triangle.
30. If triangle ABC is similar to triangle PQR (denoted as ∆ABC ~ ∆PQR), then which of the following is true?
A) AB/PQ = BC/QR = AC/PR
B) AB/QR = BC/PR = AC/PQ
C) AB/AC = BC/PQ = AC/QR
D) AB = PQ, BC = QR, AC = PR
31. Which of the following is a criterion for similarity of triangles?
A) SSS (Side-Side-Side) similarity
B) SAS (Side-Angle-Side) similarity
C) AAA (Angle-Angle-Angle) similarity
D) All of the above
32. Two triangles are said to be similar if:
A) Their corresponding angles are equal and their corresponding sides are proportional.
B) They have the same size but not necessarily the same shape.
C) They have the same shape but not necessarily the same size.
D) Their corresponding sides are equal.
33. The AAS congruence rule states that two triangles are congruent if:
A) Two angles and a non-included side of one triangle are equal to the corresponding angles and side of the other triangle.
B) Two sides and the included angle of one triangle are equal to the corresponding sides and angle of the other triangle.
C) All three sides of one triangle are equal to the corresponding sides of the other triangle.
D) All three angles of one triangle are equal to the corresponding angles of the other triangle.
34. The ASA congruence rule states that two triangles are congruent if:
A) Two angles and the included side of one triangle are equal to the corresponding angles and side of the other triangle.
B) Two sides and the included angle of one triangle are equal to the corresponding sides and angle of the other triangle.
C) All three sides of one triangle are equal to the corresponding sides of the other triangle.
D) All three angles of one triangle are equal to the corresponding angles of the other triangle.
35. The SAS congruence rule states that two triangles are congruent if:
A) Two angles and the included side of one triangle are equal to the corresponding angles and side of the other triangle.
B) Two sides and the included angle of one triangle are equal to the corresponding sides and angle of the other triangle.
C) All three sides of one triangle are equal to the corresponding sides of the other triangle.
D) All three angles of one triangle are equal to the corresponding angles of the other triangle.
36. The SSS congruence rule states that two triangles are congruent if:
A) Two angles and the included side of one triangle are equal to the corresponding angles and side of the other triangle.
B) Two sides and the included angle of one triangle are equal to the corresponding sides and angle of the other triangle.
C) All three sides of one triangle are equal to the corresponding sides of the other triangle.
D) All three angles of one triangle are equal to the corresponding angles of the other triangle.
37. If triangle ABC is congruent to triangle PQR (denoted as ∆ABC ≅ ∆PQR), then which of the following is true?
A) AB = QR
B) BC = PR
C) AC = PQ
D) AB = PQ
38. Which of the following is NOT a criterion for congruence of triangles?
A) SSS (Side-Side-Side)
B) SAS (Side-Angle-Side)
C) AAA (Angle-Angle-Angle)
D) ASA (Angle-Side-Angle)
39. Two triangles are said to be congruent if:
A) Their corresponding angles are equal
B) Their corresponding sides are proportional
C) They have the same shape and same size
D) They have the same area
40. In a right-angled triangle, the orthocenter is located at:
A) The centroid
B) The circumcenter
C) The vertex of the right angle
D) The midpoint of the hypotenuse
41. In an obtuse-angled triangle, the orthocenter lies:
A) Outside the triangle
B) On one of the sides
C) Inside the triangle
D) At the midpoint of the hypotenuse
42. In an acute-angled triangle, the orthocenter lies:
A) Outside the triangle
B) On one of the sides
C) Inside the triangle
D) At a vertex
43. The point of intersection of the altitudes of a triangle is called the:
A) Circumcenter
B) Incenter
C) Centroid
D) Orthocenter
44. Which point is equidistant from the vertices of a triangle?
A) Circumcenter
B) Incenter
C) Centroid
D) Orthocenter
45. The circumcenter of a triangle is the center of its:
A) Inscribed circle
B) Circumscribed circle
C) Exscribed circle
D) Nine-point circle
46. What is the point of intersection of the perpendicular bisectors of the sides of a triangle called?
A) Circumcenter
B) Incenter
C) Centroid
D) Orthocenter
47. The point of intersection of the angle bisectors of a triangle is called the:
A) Circumcenter
B) Incenter
C) Centroid
D) Orthocenter
48. Which point is equidistant from the sides of a triangle?
A) Circumcenter
B) Incenter
C) Centroid
D) Orthocenter
49. The medians of a triangle intersect at a point that divides each median in the ratio:
A) 1:2
B) 2:1
C) 1:1
D) 3:1
50. What is the point of intersection of the medians of a triangle called?
A) Circumcenter
B) Incenter
C) Centroid
D) Orthocenter