Online Test — Angles in Parallel Lines & Triangles
10 Questions • 20 min • Chapter MCQ
20:00
Question 1 of 10
easy
Two parallel lines are cut by a transversal. If one corresponding angle = 75 degrees, what is the other corresponding angle?
15 degrees
75 degrees
105 degrees
180 degrees
Explanation: Corresponding angles are equal when lines are parallel, so 75 degrees.
Question 2 of 10
medium
Alternate interior angles measure (4x+10) and (6x-30) degrees. Find x.
10
15
20
25
Explanation: Alternate interior angles are equal: 4x+10 = 6x-30 => 40 = 2x => x = 20
Question 3 of 10
easy
A triangle has angles 40 and 60 degrees. Find the third angle.
60 degrees
70 degrees
80 degrees
100 degrees
Explanation: 180 - 40 - 60 = 80 degrees
Question 4 of 10
medium
An exterior angle of a triangle = 110 degrees. The two remote interior angles are in ratio 5:6. Find the smaller remote interior angle.
40 degrees
50 degrees
55 degrees
60 degrees
Explanation: 5x + 6x = 110 => 11x = 110 => x = 10. Smaller angle = 5x = 50 degrees.
Question 5 of 10
medium
In a triangle, angles are x, 2x, and 3x degrees. Find the largest angle.
30 degrees
60 degrees
90 degrees
120 degrees
Explanation: x + 2x + 3x = 180 => 6x = 180 => x = 30. Largest = 3x = 90 degrees.
Question 6 of 10
medium
Consecutive interior angles measure 125 and 55 degrees. Are the lines parallel?
Yes, parallel
No, not parallel
Yes, perpendicular
Cannot determine
Explanation: 125 + 55 = 180 degrees. Consecutive interior angles summing to 180 means lines are parallel.
Question 7 of 10
easy
A transversal crosses two parallel lines. One angle formed is 120 degrees. What is its alternate interior angle?
120 degrees
60 degrees
55 degrees
30 degrees
Explanation: Alternate interior angles are equal when lines are parallel, so the angle is also 120 degrees.
Question 8 of 10
medium
Triangle has angles (x+20), (2x+10), and 60 degrees. Find x.
20
25
30
35
Explanation: (x+20) + (2x+10) + 60 = 180 => 3x + 90 = 180 => 3x = 90 => x = 30
Question 9 of 10
easy
An exterior angle is 135 degrees and one remote interior angle is 45 degrees. Find the other remote interior angle.
45 degrees
90 degrees
135 degrees
180 degrees
Explanation: Exterior angle = sum of remote interior angles. Other angle = 135 - 45 = 90 degrees.
Question 10 of 10
medium
An isosceles triangle has a vertex angle of 40 degrees. Find each base angle.
70 degrees
80 degrees
140 degrees
20 degrees
Explanation: Base angles are equal. 40 + 2b = 180 => 2b = 140 => b = 70 degrees each.