Repository: UIHistories Project: Mathematical Models Construction and Use of Mathematical Models (Fehr & Hildebrandt) [PAGE 6]

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~44#. The S l i d e R u I q * A slide r u l e h a s r e c e n t l y a p p e a r e d on the m a r k e t r e t a i l i n g for t w e n t y five c e n t s * It appears to b e s a t i s f a c t o r y in i n t r o d u c i n g the u s e f u l n e s s of the slide rule to junior and senior h i g h s c h o o l s t u d e n t s * H o w e v e r , a far grenter u n d e r s t a n d i n g of the f u n c t i o n and u s e of the slide r u l e vi 1 1 b e g a i n e d if the student c ons true ts'oil $ of h i s o w n , m a d e out of wood or c a r d b o a r d and c o s t i n g a f e w c e n t s . S t r i p s of 10n single scale l o g a r i t h m i c paper m a y b e u s e d for the C , D and C I s c a l e s ; d o u b l e scale paper for the A^and B s c a l e s , and triple scale 10n strips for the K scale;,IV.* Geometric Figures

1, Cut-out puzzles* Among the many proofs of the famous P y t h a g o r e a n T h e o r e m , appear some w h i c h can be p r o v e d b y f i t t i n g the p a r t s of t h e s q u a r e s on the legs i n t o the square on the h y p o t e n u s e of the r i g h t t r i a n g l e . P r e l i m i n a r y to this/method of v e r i f y i n g or p r o v i n g the t h e o r e m , s t u d e n t s can be g i v e n p r a c t i c e in f i t t i n g together g e o m e t r i c p o l y g o n s to f o r m l e t t e r s , s q u a r e s , and e n t e r t a i n i n g f i g u r e s * The l e t t e r s A,'S, P , H , M and T are among those com:** monly used. The l e t t e r T m a y be m a d e f r o m the four p a r t s of the a c c o m p a n y i n g figure*. 2 > A S q u a r o equal to * 20 R i g h t T r i a n g l e s • Twenty right triangles . legs 2 cm*- and 4 cm* can b e m a d e to fit a s q u a r e * (This side of the square w i l l b e 8 vr5 c m * ) 5. 6 4 - 6 5 ? This f a m o u s p r o b l e m b e l o n g s to this same -group, 4,. Tte Tanagram* This is a f a m o u s C h i n e s e puzzle*. To fit the seven p i e c e s i n to a square is an i n t e r e s t ing e x e r c i s e * Other/amusem e n t s are found in D u d e n e y , H . E • , A m u s e m e n t s in M a t h e m a t i c s , p , '43-6.*

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5*. Tfe Locuius of Archimedes.. This onsists of fourteen parts instead o f s e v e n . For f i g u r e , see S e h a a f , W * L.. ? M a t h e m a t i c s for .. Junior H i g h School T e a c h e r s , p . 4 g , ~ ~ \ 6. A r e a s of P l a n e Figures.* The p a r t s of the a c c o m p a n y i n g f i g u r e can b e r e a r r a n g e d to show that the area of a r e c t a i g l e , p a r a l l e l o g r a m , t r a p e z o i d or t r i a n g l e e c m a l s one h a l f of the p r o d u c t of the sum. of the b a s e s and the altitude.* (Figure on n e x t p , }