Click the cover to order your copy!  
 
 
This book was originally published in 2004 by Scholastic Ltd with a different cover  

Suitable for maths enthusiasts aged 10 upwards
If you want to know the length of a line or the size of an angle, you would normally measure it. But what happens when you need to know an angle accurate to 8 decimal places? And how do you measure something like the distance to a star?
EITHER... you have to hand over a massive amount of cash to buy Professor Fiendish's latest invention "The Angletron"OR... you can use trigonometry! 
This book deals with one of the most amazing parts of maths. You'll discover how to:
Don't forget to click the EXTRA links for more details that we didn't have room for in the book!
Professor Fiendish breaks into the MM offices and writes an unexpected introduction to the book!
The Geometry Set SelfAssessment Test! Many thanks to all the people who have contacted us and told us their score. Here is a summary of the results. 
Here are what the scores say about you... * 010 Your nurse shouldn't be letting you near a geom set. * 1125 Bank manager * 2640 Super cool person * 4155 Your brain is a national treasure * 56100 Utterly Nutty Pure Mathematician * over 100 URGENT! You need to read ESSENTIAL ARITHMETRICKS 
What is trigonometry, and geometry, and how can we stop calculators rebelling?
What kind of person are you? Should you be leading dangerous expeditions through jungles? Or should your nurse be keeping you somewhere safe? Find out by checking the contents of your geometry set and doing the selfassessment test. You'll also find out the correct way to use a protractor and how NOT to lend somebody your dividers.
Join the Fogsworths as they discover how useless a map on a scale of 100,000:1 is, shrink and stretch the professor as you discover all about ratios and see what similar triangles are.
How to draw triangles so accurately that you can check your calculator with them. Discover the sneaky secret of the excluded angle  and how it helps Dolly Snowlips keep Blade and the gang from digging up Bluetooth's Buried Bullion.
Thanks to Mark who sent us this nice "SOHCAHTOA": Signs Of Happiness Come After Having Tankards Of Ale 
By now the Professor is smirking because his "Angletron" can measure angles accurate to 0.001º but you'll soon wipe the smile off his face! When you know about SIN COS and TAN you can work out angles accurate to 0.0000001º or even better! For a bit of practise we use SIN and COS to help the utterly nutty Pure Mathematicians design a slide that goes straight into their duck pond. Then we calculate the height of a giant with TAN and finally there's the ridiculous but true story of where the word SINE comes from and how it gets shortened to SIN!
Does your calculator have buttons such as SIN COS TAN and SHIFT or INV or 2nd FCN? Then this is the chapter for you  because you'll find out exactly what they're for! You can turn fractions into angles and back again, and soon you'll have enough calculating power to seriously upset the professor. You also find out things like why sin30º = 0.5, and how to work out sin values with your geometry set. Finally there's three missions to deal with  stop the Evil Gollarks stealing some free air  avoid the waste dripping from the Leaning Tower of Fastbuck and help Thag beat Urgum the Axeman and Grizelda the Grisly to the Stones of Healing.
Just when we've learnt how to defeat any rightangled triangle, Professor Fiendish starts playing dirty!
He kicks the right angles away and challenges us to measure them  but help is at hand with the the superheros Supersin and Cosgirl who save the day with their awesome sin and cosine formulas. Even Tandog has a trick formula for polygon areas. There's also an extract from Shakespeare's long forgotten play Henry X11 part 5 and finally... the secret identites of the superheros are revealed.
How do you measure the distance to the 13th hole on the MM executive golf course? The answer's all in here... triangulation.
Find out about arcminutes, arcseconds, parsecs, parallax and apparent angles as you see how good your eyesight is and work out measurements to distant stars. Meanwhile the Gollarks are waiting to get home and somebody is still trying to sell us his angletron.
EXTRA: Here's what the author looked like as he was writing this chapter!
Professor Fiendish is getting so desperate that he tries stealing the SIN and COS buttons from our calculator. Luckily we know enough about trig to find other clever ways to get the answers.

We take a boat trip and learn how to find our position on a map using a compass and bearings. We then see how Riverboat Lil cheats Brett Shuffler with a dodgy treasure map, and finally we manage to locate a sunken wreck!
At last the professor catches up with us, and challenges us with a diabolical diagram. It's a race between his angletron and our powers of trig, and it calls upon all the tricks and cunning we've picked up in the book. And it's a very close... but completely unexpected finish!