## Welcome to H3 Maths

Blog Support for Growing Mathematicians

## Posts tagged with angles

### Be a Number Wizz with Scott Flansburg

October24

Where did we get our number system from? Watch Scott Flansburg amaze with his addition skills and be equally transformed as he explains that our number system is based on angles. Yes, Trigonometry is the foundation of Number, or is Number the foundation of Trigonometry? Are you getting confused? Find out more in this video, […]

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### Angles of Depression and Elevation

September13

Angles of Depression and Angles of Elevation both relate to the view from a horizontal line. When someone is depressed they tend to look down and the same is true for an angle of depression – it is an angle looking down from an imaginary horizontal line. In the sketch below, imagine someone in the […]

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### The Three Trig Ratios

August8

If you look at a scientific calculator you will notice that there are three unusual buttons labelled “Sin”, “Cos” and “Tan”. These are the 3 Trig Ratios, used to find the length of sides on a right-angled triangle (like the one below). I have found, from years of teaching, that it is easiest to remember […]

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### Bart’s Dog Knows a few Angles

June10

The blog slowed down a little over this long weekend but, even on holiday, I simply cannot resist seeing something mathematical around me. Take this dog pic for instance. Taken on the Gold Coast on Saturday morning, it shoes Bart’s dog chasing a ball thrown by Melissa and Chelsea (our two young mathematicians). A is […]

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### No touching allowed

September19

Parallel lines are lines in the same plane that never touch. Like railway tracks they just keep the same distance apart: Which leads to some interesting facts about angles…read more here. So, are the railway tracks on the right in this picture parallel or not? This question generated quite a bit of class discussion. Of […]

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### How do you measure up?

September13

Yes, a number of students (perhaps even you?) have difficulty measuring angles accurately. First, you need a protractor, something like this: You place the centre of the protractor (labelled G above) on the vertex (place where the angle is formed). You move the protractor around until the 0 degree mark is at the start of […]

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#### Post Support

The graph on the left (Coronavirus) is for a time period of 30 days, while the one on the right (SARS) is for 8 months! Very poor graphical comparison and hardly relevant, unless it is attempting to downplay the seriousness of the coronavirus?

10 x 9 x 8 + (7 + 6) x 5 x 4 x (3 + 2) x 1 = 2020

NCEA Level 2 Algebra Problem. Using the information given, the shaded area = 9, that is:
y(y-8) = 9 –> y.y – 8y – 9 =0
–> (y-9)(y+1) = 0, therefore y = 9 (can’t have a distance of – 1 for the other solution for y)
Using the top and bottom of the rectangle,
x = (y-8)(y+2) = (9-8)(9+2) = 11
but, the left side = (x-4) = 11-4 = 7, but rhs = y+? = 9+?, which is greater than the value of the opp. side??
[I think that the left had side was a mistake and should have read (x+4)?]