Worksheet Chapter 8: Lines and Angles

1. Fill in the blank: The sum of two complementary angles is ________ degrees.

2. Angles at a point are given as 3x°, 2x°, 70°, and 90°. Calculate the value of x and state the largest angle among them.

3. Three angles lie on a straight line: x°, (x + 10)°, and 50°. Calculate the value of x.

4. An observer on a cliff measures the angle of depression of a boat in the sea to be 38°. State the angle of elevation of the observer as seen from the boat.

5. Two parallel lines are cut by a transversal line. If one interior angle is 65°, find the measure of its adjacent interior angle on the same side of the transversal.

6. Find the conjugate angle of 215°.

7. In a diagram, line AB is parallel to line CD. A transversal EF intersects AB at P and CD at Q. If angle APQ = (4x - 10)° and alternate angle PQD = (2x + 30)°, calculate the value of x and the actual angle measure.

8. Which of the following angles is an obtuse angle?

9. True or False: Interior angles on the same side of a transversal intersecting two parallel lines are equal.

10. True or False: Vertically opposite angles are always equal to each other when two straight lines intersect.