Geometry: lines angles triangles and basic theorems including Pythagoras. - Question Bank

1. If a transversal intersects two lines such that the sum of the interior angles on the same side is 180 degrees, then the two lines are:
A) Intersecting
B) Parallel
C) Perpendicular
D) Skew
2. Which of the following is NOT a type of triangle based on angles?
A) Acute triangle
B) Isosceles triangle
C) Obtuse triangle
D) Right triangle
3. If a triangle has sides of length 6, 8, and 10, what is its area?
A) 24 sq units
B) 48 sq units
C) 60 sq units
D) 100 sq units
4. The converse of the Pythagorean theorem states that if the square of the longest side of a triangle is equal to the sum of the squares of the other two sides, then the triangle is:
A) Acute
B) Obtuse
C) Right-angled
D) Isosceles
5. What is the property of angles on a straight line?
A) They are equal.
B) Their sum is 90 degrees.
C) Their sum is 180 degrees.
D) Their sum is 360 degrees.
6. In an isosceles triangle, if the vertex angle is 80 degrees, what is the measure of each of the base angles?
A) 50 degrees
B) 80 degrees
C) 100 degrees
D) 20 degrees
7. If a right triangle has legs of length 'a' and 'b', and hypotenuse 'c', the area of the triangle can be calculated as:
A) a * b
B) (a * b) / 2
C) (a + b) / 2
D) c^2 / 2
8. The theorem that 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 is known as:
A) Pythagorean Theorem
B) Basic Proportionality Theorem (or Thales' Theorem)
C) Angle Bisector Theorem
D) Median Theorem
9. Which geometric figure is defined by three non-collinear points?
A) A line
B) A plane
C) A triangle
D) An angle
10. In a triangle, if one angle is obtuse, the other two angles must be:
A) Obtuse
B) Right
C) Acute
D) Straight
11. If a triangle has sides of length 8, 15, and 17, what type of triangle is it?
A) Acute triangle
B) Obtuse triangle
C) Right triangle
D) Equilateral triangle
12. What is the measure of an angle that is complementary to a 40-degree angle?
A) 40 degrees
B) 50 degrees
C) 90 degrees
D) 130 degrees
13. What is the measure of an angle that is supplementary to a 70-degree angle?
A) 20 degrees
B) 70 degrees
C) 110 degrees
D) 180 degrees
14. An angle greater than 180 degrees but less than 360 degrees is called a:
A) Obtuse angle
B) Acute angle
C) Right angle
D) Reflex angle
15. If a triangle has sides of length 5, 12, and 13, is it a right triangle? (Hint: Use the converse of the Pythagorean theorem).
A) No, because 5 + 12 is not 13.
B) Yes, because 5^2 + 12^2 = 13^2 (25 + 144 = 169).
C) No, because the sides are not equal.
D) Yes, because it has three sides.
16. In a triangle, the sum of any two sides is always greater than the third side. This is known as the:
A) Pythagorean Inequality
B) Triangle Inequality Theorem
C) Angle Sum Property
D) Exterior Angle Theorem
17. What is a ray?
A) A line segment with two endpoints.
B) A part of a line with one endpoint and extending infinitely in one direction.
C) A line extending infinitely in both directions.
D) A closed curve.
18. If two lines are perpendicular, they intersect at an angle of:
A) 0 degrees
B) 45 degrees
C) 90 degrees
D) 180 degrees
19. A triangle with angles 30, 60, and 90 degrees is a special type of:
A) Isosceles triangle
B) Obtuse triangle
C) Equilateral triangle
D) Right triangle
20. Which theorem states that in a right-angled triangle, the square on the hypotenuse is equal to the sum of the squares on the other two sides?
A) Euclid's Theorem
B) Thales' Theorem
C) Pythagorean Theorem
D) Angle Sum Property Theorem
21. If a line segment AB has endpoints A(2, 3) and B(7, 9), what is the length of AB?
A) sqrt(5^2 + 6^2)
B) sqrt(7^2 + 9^2)
C) sqrt(2^2 + 3^2)
D) sqrt(5^2 - 6^2)
22. In a triangle ABC, if angle A = 50 degrees and angle B = 60 degrees, what is the measure of angle C?
A) 50 degrees
B) 60 degrees
C) 70 degrees
D) 80 degrees
23. What is the sum of the exterior angles of any convex polygon, one at each vertex?
A) 180 degrees
B) 360 degrees
C) Dependent on the number of sides
D) 0 degrees
24. A closed figure formed by three line segments is called a:
A) Quadrilateral
B) Triangle
C) Pentagon
D) Hexagon
25. A point where two or more lines or line segments meet is called a:
A) Line
B) Angle
C) Vertex
D) Ray
26. If two parallel lines are intersected by a transversal, the consecutive interior angles (or same-side interior angles) are:
A) Equal
B) Complementary
C) Supplementary
D) Perpendicular
27. If two parallel lines are intersected by a transversal, the corresponding angles are:
A) Supplementary
B) Complementary
C) Equal
D) None of the above
28. If two parallel lines are intersected by a transversal, the alternate interior angles are:
A) Supplementary
B) Complementary
C) Equal
D) None of the above
29. What is the measure of each angle in an equilateral triangle?
A) 30 degrees
B) 45 degrees
C) 60 degrees
D) 90 degrees
30. If a right triangle has legs of length 3 units and 4 units, what is the length of the hypotenuse?
A) 5 units
B) 6 units
C) 7 units
D) 8 units
31. According to the Pythagorean theorem, in a right triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides. If 'c' is the hypotenuse and 'a' and 'b' are the other two sides, which equation represents this theorem?
A) c = a + b
B) c^2 = a^2 - b^2
C) c^2 = a^2 + b^2
D) a^2 + c^2 = b^2
32. The Pythagorean theorem relates the sides of which type of triangle?
A) Equilateral triangle
B) Isosceles triangle
C) Scalene triangle
D) Right triangle
33. The side opposite the right angle in a right triangle is called the:
A) Perpendicular
B) Base
C) Hypotenuse
D) Altitude
34. In an isosceles triangle, the angles opposite the equal sides are:
A) Unequal
B) Right angles
C) Equal
D) Supplementary
35. A triangle with all three angles measuring less than 90 degrees is called an:
A) Obtuse triangle
B) Right triangle
C) Acute triangle
D) Scalene triangle
36. A triangle with one angle measuring more than 90 degrees is called an:
A) Right triangle
B) Acute triangle
C) Obtuse triangle
D) Isosceles triangle
37. A triangle with one angle measuring 90 degrees is called a:
A) Acute triangle
B) Obtuse triangle
C) Right triangle
D) Equilateral triangle
38. A triangle with no sides of equal length is called a:
A) Isosceles triangle
B) Equilateral triangle
C) Scalene triangle
D) Acute triangle
39. A triangle with at least two sides of equal length is called an:
A) Equilateral triangle
B) Isosceles triangle
C) Scalene triangle
D) Obtuse triangle
40. A triangle with all three sides of equal length is called an:
A) Isosceles triangle
B) Scalene triangle
C) Equilateral triangle
D) Right triangle
41. What is the sum of the angles in any triangle?
A) 90 degrees
B) 180 degrees
C) 270 degrees
D) 360 degrees
42. A pair of adjacent angles whose non-common sides form a straight line is called a:
A) Complementary pair
B) Supplementary pair
C) Linear pair
D) Vertical pair
43. Angles that share a common vertex and a common side but do not overlap are called:
A) Vertical angles
B) Complementary angles
C) Adjacent angles
D) Linear pair angles
44. Two angles are supplementary if the sum of their measures is:
A) 90 degrees
B) 180 degrees
C) 270 degrees
D) 360 degrees
45. Two angles are complementary if the sum of their measures is:
A) 90 degrees
B) 180 degrees
C) 270 degrees
D) 360 degrees
46. When two lines intersect, the angles opposite each other at the intersection point are called:
A) Adjacent angles
B) Complementary angles
C) Vertical angles
D) Supplementary angles
47. What is the measure of a straight angle?
A) 0 degrees
B) 90 degrees
C) 180 degrees
D) 360 degrees
48. An angle measuring less than 90 degrees but greater than 0 degrees is called a(n):
A) Obtuse angle
B) Reflex angle
C) Right angle
D) Acute angle
49. Which type of angle measures exactly 90 degrees?
A) Acute angle
B) Obtuse angle
C) Right angle
D) Straight angle
50. What is the definition of a line segment?
A) A part of a line that extends infinitely in both directions.
B) A part of a line that has two endpoints.
C) A part of a line that has one endpoint and extends infinitely in one direction.
D) A closed figure formed by three or more line segments.