10 questions · Form 1 Mathematics Bab 8: Lines and Angles
What type of angle measures between 180° and 360°?
Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.
1. What type of angle measures between 180° and 360°?
Answer: C
A reflex angle is defined as an angle that is greater than 180° but less than 360°.
2. If the angle of elevation of a kite from a person standing on the ground is 42°, what is the angle of depression of the person from the kite?
Answer: C
The angle of elevation from point A to point B is equal to the angle of depression from point B to point A due to alternate interior angles.
3. Three angles on a straight line are x°, 45°, and 65°. Calculate the value of x.
Answer: C
Angles on a straight line sum to 180°. x + 45 + 65 = 180 => x + 110 = 180 => x = 70.
4. Two straight lines intersect at a point. If one angle is 125°, what is the measure of its vertically opposite angle?
Answer: B
Vertically opposite angles formed by intersecting lines are equal, so the angle is 125°.
5. When a transversal cuts two parallel lines, which geometric shape rule helps identify alternate angles?
Answer: B
Alternate angles lie on opposite sides of a transversal between parallel lines and form a 'Z' shape (or inverted Z).
6. If two interior angles on the same side of a transversal are (2x)° and 80°, find x given the lines are parallel.
Answer: A
Interior angles on the same side of a transversal add up to 180°. 2x + 80 = 180 => 2x = 100 => x = 50.
7. If angle x and angle y are complementary angles, and x = 35°, what is the value of y?
Answer: A
Complementary angles add up to 90°. Therefore, y = 90° - 35° = 55°.
8. A line that divides an angle into two equal parts is called an...
Answer: B
An angle bisector is a ray or line segment that splits an angle into two congruent angles.
9. An observer at the top of a lighthouse looks down at a boat on the sea. What is the angle between the horizontal line of sight and the observer's line of sight to the boat called?
Answer: C
The angle formed between the horizontal line of sight and an object below the observer is called the angle of depression.
10. Four angles surrounding a point are 2x°, 3x°, 100°, and 110°. Find the value of x.
Answer: A
Sum of angles at a point = 360°. 2x + 3x + 100 + 110 = 360 => 5x + 210 = 360 => 5x = 150 => x = 30.