# NRICH PROBLEM SOLVING ANGLES

I would not use a protractor like the one above for work like this. Weekly Problem 39 – If you know three lengths and an angle in this diagram, can you find another angle by calculation? Cartesian Isometric Age 7 to 11 Challenge Level: Olympic Turns Age 7 to 11 Challenge Level: Weekly Problem 50 – The diagram shows a regular dodecagon. How many guesses do you need to find the robber? How would you turn at each junction? What is the sum of the three marked angles? Filter by resource type problems games articles general resources interactive environment EYFS Resources projects Lists Filter by age 5 to 7 7 to 11 11 to 14 14 to 16 16 to What is the side length of the original triangle? Round a Hexagon Age 7 to 11 Challenge Level:

Pegboard Quads Age 14 to 16 Challenge Level: Circle Theorems Age 14 to 16 Challenge Level: Weekly Problem 53 – The diagram shows a regular pentagon and regular hexagon which overlap. Can you work out the area of a square drawn on a diagonal? Show how this pentagonal tile can be used to tile the ajgles and describe the transformations which map this pentagon to its images in the tiling.

## Angles Inside

Weekly Problem 50 – The diagram shows a regular dodecagon. Lunar Angles Age 16 to 18 Challenge Level: How many octahedra can you fit around this solvign Weekly Problem 27 – Four congruent isosceles trapezia are placed in a square.

Angle Trisection Age 14 to 16 Challenge Level: The exercise itself was repeated twice more over the page. Cubestick Age 16 to anlges Challenge Level: What is the size of angle TQR?

# Angle Hunt :

Discuss and Choose Age 5 to 11 Challenge Level: What are the remaining angles in the right-angled triangle in the same figure? Quadrilaterals Age 7 nric 11 Challenge Level: You may also like Right Time At the time of writing the hour and minute hands of my clock are at right angles. Where does the crease meet the side AD? 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.

What proportion of the area of the tessellation is shaded? How much do you have to turn these dials by in order to unlock the safes? What other triangles could you make if you had a rope like this?

# Estimating Angles :

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. If the shape on the inside is a rectangle, what can you say about the shape on the outside? 