In mathematics, a straight line is defined as a line followed by a point travelling in a constant direction with no curvature. Straight lines connect two points shortest distance.
Lines can be divided into many types, such as horizontal, perpendicular, vertical, and parallel.
Lines
Horizontal line
When a line moves from east to west, it is horizontal.
Perpendicular line
When any two lines meet each other at an angle of 90° is called a perpendicular line.
Vertical line
A straight line from up to down is called a vertical line.
Parallel line
When any two lines don't meet, touch, or intersect even at infinity, that line is called a parallel line.
Tangent
A straight line that touches the curve is called a tangent at any given point.
Angles
An angle is formed when two rays are united at a common point. An angle is usually measured in degrees, radians, or gradians.
Acute angles are formed between 0° to 90°.
An obtuse angle is formed between 90° to 180°.
An angle equal to 180°>is called a straight angle.
Reflex angles are greater than 180° and less than. 360°.
And an entire rotation of an angle leads to 360°.
LEARN BY DOING
Free Lines and Angles Olympiad Questions for Class 11
5 questions to build confidence. Choose an answer, then explore the explanation.
01
Given that AC = 19 and AB = 11, find the measure of Angle B. Round to the nearest whole degree.
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The answer key for this sample question is not available yet.
02
Given two vectors, with magnitudes 8 and 4, which have a common initial point and an angle of 37° between them, what is the resulting vector if they are added together, given as a magnitude and direction? Let the calculated angle be relative to the vector of magnitude 4. Hint: use the parallelogram rule.
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Answer: B. Magnitude 11.5, angle 24.9°.
Using the parallelogram rule, the resultant magnitude is about 11.5 and the angle relative to the 4-vector is about 24.9°.
03
What is the sum of the interior angles of a quadrilateral?
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The answer key for this sample question is not available yet.
04
Which of these transformations will create a shape which is not congruent with the original?
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The answer key for this sample question is not available yet.
05
If a line is drawn between I and the origin, what is the angle between this line and the positive x-axis, starting from the x-axis and going in a counterclockwise direction? Let beta represent this angle.
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Answer: B. beta = 53.1°
This is the standard angle for a line with rise/run matching a 3-4-5 triangle, giving arctan(4/3) ≈ 53.1°.
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