ANGLES

By: Anna

WHAT IS AN ANGLE?An angle is when two rays share a

vertexThere are five types of angles

acute, obtuse, reflex ,straight, and right.

ACUTE ANGLESAcute angles are less than 90 degrees.

Acute angle

OBTUSE ANGLESAn obtuse angle is bigger than 90

degrees but smaller than 180 degrees.

Obtuse angle

RIGHT ANGLES

Right angles are exactly 90 degrees

Right angle

STRAIGHT ANGLES

A straight angle is exactly 180 degrees.

Straight Angles

ESTIMATING ANGLES To estimate angles you can use 45,90,135,

and 180 degree angles as reference angles. You do this by taking a piece of paper and

folding one of the corners in until it reaches the side of the paper.

45 degree angle

135 degree angle

90 degree angle

PROTRACTORS A protractor is a tool used for measuring

angles On a protractor there is a baseline, midpoint,

inner scale, and outer scale. On a protractor angles are represented in

degrees.

MEASURING ANGLES

How to measure angles:

First: you align the vertex of the angle with the midpoint of the protractor.

Second: you make sure that the bottom ray of angle Is aligned with the baseline of the protractor.

Third: you look at the top ray. The line that it is on indicates the degree of the angle.

A common mistake made while estimating angles is using the wrong scale. To avoid this, make sure that if your measuring an acute angle the scale you use has a smaller number and vise versa.

DRAWING ANGLESFirst: you make a vertex on the page your drawing the angle on. Be careful not to make it too big.

Second: you make a dot on the edge of the baseline. Then you connect the dots with a ruler. This should form your bottom ray.

Third: you make a dot on the degree that you want your angle to be. Then you connect the dots.(your vertex and top ray)

SUCCESSES I succeeded in drawing

angles. At first it was a bit confusing … but after that I really understood and enjoyed drawing angles.

I'm also pretty good at estimating angles. I really got the hang of it after practicing estimating angles.

CHALLENGES I struggled a bit in

measuring angles. I either use the wrong scale or …just don’t take my time and ended up with an inaccurate measurement.

I will practice measuring angles and try to take my time measuring so I don’t mess up. I’ll also pay more attention to the scale I use.

THANKS FOR WATCHING MY PRESENTATION ON ANGLES