Perpendicular and Parallel lines.

Perpendicular and Parallel lines.

Hello! Today I will teach you about lines. These are important mathematics that are all around the world.

Perpendicular lines

• Perpendicular lines are all straight

• Perpendicular lines has a 90 degrees angle where the lines intersect.

• All the images on the screen are perpendicular lines.

Parallel lines

• Notice that parallel lines NEVER touch each other.

• Parallel lines go on forever.

Multiple Choice

Which one of these are a perpendicular line feature

• It always has a 1 degree angle where the lines intersect

• The lines are always slanted.

• Perpendicular lines are thinner than a centimeter

• Perpendicular lines are always straight.

Angles

Angles are also found a lot in these lines. They are also very important to the world, and everywhere you see, you find them.

Different type of angles.

• Complementary angles: These angles are angles that add up to 90 degrees.

• Supplementary angles: These angles add up to exactly 180 degrees.

Multiple Choice

These are Complementary angles. Find the value of angle b if angle a is 49 degrees.

• 65 degrees.

• 311 degrees

• 51 degrees

• 62 degrees

Types of angles (2)

• Vertical angles: are the opposite angles when 2 lines cross (x)

• When 2 parallel lines are crossed by another line, the angles in matching corners are called corresponding angles (F)

Types of angles 2 (continued)

• The angles that are formed on opposite sides of the transversal and inside the 2 lines are alternate interior angles (z)

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How to understand what I typed.

If you didn't really understand what I just said (not the words above, the words on the slide 9 and 10), you can draw pictures of the angles, then, you might be able to understand better.

Open Ended

(Review) Please tell me about perpendicular and parallel lines, and types of angles. (Some of the content are notes I've wrote down from math class.