# NRICH PROBLEM SOLVING ANGLES

Which ones are impossible? Register for our mailing list. During the third hour after midnight the hands on a clock point in the same direction so one hand is over the top of the other. A semicircle is drawn inside a right-angled triangle. The ancient Egyptians were said to make right-angled triangles using a rope with twelve equal sections divided by knots. Find the exact values of some trig. Square Within a Square Within

Being Collaborative – Primary Age 5 to 11 These problems are ideal for primary school children to work on with others. Suggestions for worthwhile mathematical activity on the subject of angle measurement for all pupils. Weekly Problem 21 – Two rectangles are drawn in a rectangle. Find the exact values of some trig. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice. Can you explain why and does this rule extend beyond angles of 90 degrees?

Join pentagons together edge to edge. Olympic Turns Age 7 to 11 Challenge Level: At the time of writing the hour and minute hands of my clock are at right angles. Lunar Angles Age 16 to 18 Challenge Level: To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional agnles for teachers wishing to embed rich mathematical tasks into everyday classroom practice.

SDMS HOMEWORK GREEN

Weekly Problem 51 – Each interior angle of a particular polygon is an obtuse angle which is a whole number of degrees. Weekly Problem 8 – Are you able to find triangles such that these five statements are true?

## 349 Matches for estimating angles

Can you do this without drawing them? What other triangles could you make if you had a rope like this? How many rhombuses are there made up of two adjacent small triangles?

Now, what other relationships you can see? What is the size of the marked angle? Sine and Cosine Age nrlch to 16 Challenge Level: Some questions they could be asked might include:.

Which ones are impossible? That is, pupils were given almost one hundred and fifty opportunities to repeat the same task.

Weekly Problem 15 – How many of the five properties can a heptagon have? The Cyclic Quadrilateral Age 11 to 16 This gives a short summary of the properties and theorems of cyclic quadrilaterals and links to some practical examples to be found elsewhere on the site.

Of course, with solvig geometry software, any number can be produced and then copied for pupil use.

Can you work out how these polygon pictures were drawn, and use that to figure out their angles? What anlges the sum of the four marked angles?

Printable worksheets containing selections of these problems are available here: Can you work out the length of its base? Discover some angle relationships.

## Estimating Angles

Turning Age 5 to 7 Challenge Level: Register for our mailing list. How long is the fence?

Overbearing Age 11 to 14 Short Challenge Level: The sine of an angle is equal to the cosine of its complement. Weekly Problem 44 – A garden has the shape of a right-angled triangle. Find the missing distance in this diagram with two isosceles triangles.

# Angle Hunt :

What fraction of the square is shaded? What shapes should Elly cut out to make a witch’s hat? What if the triangle is on the surface of a sphere? Draw some angles inside a rectangle.