Q.1 What is the sum of angles on a straight line?
90°
180°
270°
360°
Explanation - The angles on a straight line always add up to 180°.
Correct answer is: 180°
Q.2 If two angles are complementary, their sum is:
90°
120°
180°
360°
Explanation - Complementary angles add up to 90°.
Correct answer is: 90°
Q.3 Angles forming a linear pair are always:
Equal
Right angles
Supplementary
Complementary
Explanation - Linear pair of angles always add up to 180° (supplementary).
Correct answer is: Supplementary
Q.4 What is the sum of the interior angles of a triangle?
90°
120°
180°
360°
Explanation - The sum of interior angles of any triangle is 180°.
Correct answer is: 180°
Q.5 In an equilateral triangle, each angle measures:
45°
60°
90°
120°
Explanation - All angles in an equilateral triangle are equal and measure 60°.
Correct answer is: 60°
Q.6 Two lines which never intersect are called:
Parallel lines
Perpendicular lines
Secants
Intersecting lines
Explanation - Parallel lines remain equidistant and never intersect.
Correct answer is: Parallel lines
Q.7 Two lines intersect to form a right angle. These lines are called:
Parallel
Skew
Perpendicular
Secant
Explanation - When two lines meet at 90°, they are perpendicular.
Correct answer is: Perpendicular
Q.8 If one angle of a triangle is 90°, the triangle is called:
Equilateral
Right-angled
Isosceles
Scalene
Explanation - A triangle with one 90° angle is called a right-angled triangle.
Correct answer is: Right-angled
Q.9 In a triangle, the side opposite the largest angle is always:
The smallest
Equal to the smallest
The longest
Median
Explanation - In any triangle, the side opposite the largest angle is the longest.
Correct answer is: The longest
Q.10 What is the measure of each angle in a regular triangle?
45°
60°
90°
120°
Explanation - A regular (equilateral) triangle has all angles equal to 60°.
Correct answer is: 60°
Q.11 What type of angles are vertically opposite angles?
Equal
Supplementary
Complementary
Right
Explanation - When two lines intersect, opposite angles are always equal.
Correct answer is: Equal
Q.12 If two angles are supplementary and one angle is 70°, the other is:
20°
30°
110°
90°
Explanation - Supplementary angles add to 180°. So, 180 - 70 = 110°.
Correct answer is: 110°
Q.13 Which triangle has two equal sides?
Scalene
Equilateral
Isosceles
Right
Explanation - An isosceles triangle has exactly two equal sides.
Correct answer is: Isosceles
Q.14 What is the angle between the hands of a clock at 3 o'clock?
30°
60°
90°
120°
Explanation - At 3 o’clock, the hands form a right angle of 90°.
Correct answer is: 90°
Q.15 If one angle of a triangle is obtuse, the triangle is called:
Acute-angled
Right-angled
Obtuse-angled
Equilateral
Explanation - A triangle with one angle greater than 90° is obtuse-angled.
Correct answer is: Obtuse-angled
Q.16 If all three sides of a triangle are different, it is called:
Equilateral
Isosceles
Scalene
Right
Explanation - A scalene triangle has all sides of different lengths.
Correct answer is: Scalene
Q.17 If two angles of a triangle are 45° and 55°, the third angle is:
80°
90°
100°
120°
Explanation - Sum of angles in a triangle is 180°. So, 180 - (45 + 55) = 80°.
Correct answer is: 80°
Q.18 The exterior angle of a triangle is equal to:
Sum of two opposite interior angles
Sum of all angles
One of the interior angles
Difference of two interior angles
Explanation - Exterior angle of a triangle equals the sum of the two opposite interior angles.
Correct answer is: Sum of two opposite interior angles
Q.19 A triangle with all angles less than 90° is:
Right triangle
Obtuse triangle
Acute triangle
Scalene triangle
Explanation - When all angles are less than 90°, the triangle is acute.
Correct answer is: Acute triangle
Q.20 If a transversal cuts two parallel lines, corresponding angles are:
Equal
Supplementary
Complementary
Unequal
Explanation - When a transversal cuts parallel lines, corresponding angles are equal.
Correct answer is: Equal
Q.21 If a transversal cuts two parallel lines, alternate interior angles are:
Equal
Supplementary
Complementary
Right
Explanation - Alternate interior angles are equal when parallel lines are cut by a transversal.
Correct answer is: Equal
Q.22 How many medians does a triangle have?
1
2
3
4
Explanation - Every triangle has 3 medians, one from each vertex.
Correct answer is: 3
Q.23 The centroid of a triangle is the point of intersection of:
Medians
Altitudes
Perpendicular bisectors
Angle bisectors
Explanation - Centroid is the common point where all medians intersect.
Correct answer is: Medians
Q.24 The orthocenter of a triangle is the point of intersection of:
Medians
Altitudes
Perpendicular bisectors
Angle bisectors
Explanation - Orthocenter is where the altitudes of a triangle meet.
Correct answer is: Altitudes
Q.25 In a right-angled triangle, the side opposite the right angle is called:
Base
Height
Hypotenuse
Median
Explanation - The side opposite the right angle in a right triangle is the hypotenuse.
Correct answer is: Hypotenuse