2. Make these angles with sticks (matches will do): right angle, acute angle, obtuse angle.

3. Get a protractor (this is an instrument used for measuring angles). Draw a straight line just a little longer than the straight edge of the protractor. Call it AB. Hold the protractor over AB, so that the point A is just under the middle of the straight edge of the protractor and the line AB runs along, under the protractor, to the figure 0. Put a tick just where this line on the protractor touches your line AB.

Now count along your protractor 20 little ticks up (these little divisions are called degrees) and put a tick on the paper at the edge of the protractor. Take away the protractor and join this tick to A. Call the line AC.

You have made an angle, and the point where AB and AC meet (the corner) contains 20 degrees.

Now draw another straight line, and make an angle of 90 degrees. Don't forget to give the angle a name by putting letters at its points.

Draw another straight line, and make an angle of 120 degrees. A Right Angle contains 90 degrees, an Acute Angle contains less than 90 degrees, and an Obtuse Angle contains more than 90 degrees. A Straight Angle contains two right angles (180 degrees). The lines of an angle are called its Arms, and the point where they meet is called the Vertex. It does not

matter how long or short the arms of an angle are made, the size of the angle does not change.

Now draw any kind of angle you like, without using the protractor, then measure with the protractor how many degrees it contains.

You can use the sign for degrees, and the sign ▲ for angle. Practise making different angles with two fingers. Give their name in each case till you are quite certain which is which.

IV

STORY OF THE TRIANGLE FAMILY

THE DIFFERENT TRIANGLES

THE Triangle family were not good-looking.

Equilateral, the eldest, was a cheerful little fellow. The angles of his face never changed. But the top of his head was so pointed that he could not have kept many brains there.

Isosceles, the second boy, was gloomy and disagreeable. His chin was so pointed that it was painful to bump up against it.

Scalene, the third boy, was always out of

sorts, and had screamed so much that his mouth was quite crooked.

But one day a new Triangle baby arrived. He was a mixture of his brothers-Equilateral, Isosceles and Scalene were all to be found in different parts of his body and in the queer workings of his little mind. His name was, of course, Equisoscelene (which you will note is a mixture of the names of the other three), but we will call him plain Tommy Triangle, for short. Here is his portrait :

Tommy Triangle was a great trial to his parents; for he had a habit of falling to pieces.

"There's Tommy, all in bits again! exclaimed Mrs. Triangle one day as she stumbled over something in the larder. It was evident that Master Tommy had been trying to help himself to jam, but the jam was on the top shelf in the larder, and in trying to reach it Tommy had had an accident, and there he lay-in pieces-on the floor, with a chair lying across his body and a smashed jam-pot, with its contents, sitting smearily on his face.

"Come and help to put him together! cried Mrs. Triangle, and all the little Triangles rushed up and examined the bits.

"His cap is like me, all its sides are equal," said little Equilateral, seizing Tommy's cap. "His face resembles mine: two of its sides