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°.
Lines and Angles Sample Questions for Class 11
Question 1
Given that AC = 19 and AB = 11, find the measure of Angle B. Round to the nearest whole degree.
A. 60deg
B. 30deg
C. 70deg
D. 85deg
Question 2
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.
A. Magnitude 11.5, angle 12.1°.
B. Magnitude 11.5, angle 24.9°.
C. Magnitude 5.4, angle 35.9°.
D. Magnitude 5.4, angle 17.1°.
Question 3
What is the sum of the interior angles of a quadrilateral?
A. 180deg
B. 270deg
C. 360deg
D. 540deg
Question 4
Which of these transformations will create a shape which is not congruent with the original?
A. Rotate 90 deg clockwise and dilate by a factor of 2
B. Translate 4 to the left and rotate 180 deg
C. Translate down 2, reflect across the y axis, and rotate 180 deg
D. Reflect across the x axis and translate down by 6
Question 5
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.
A. beta = 45.0°
B. beta = 53.1°
C. beta = 36.9°
D. beta = 48.6°