Question

Alicia draws an equilateral triangle and then rotates it about its center.

Through which angle measures can she rotate the equilateral triangle to map it onto itself?

Answer 1

@Will.H @welshfella

Answer 2

@agent0smith

Answer 3

@MrNood @welshfella @zepdrix

Answer 4

i got 180... is there any other?

Answer 5

180 won't work (try it - imagine rotating it 180 degrees)

Answer 6

ohh yeah i see it now

Answer 7

it would look like that

Answer 8

ok so what would work?

Answer 9

Rotate it so it looks the same, and keep doing that until you get back to the way it started. How many times can you rotate it before it gets back to the way it started?

Answer 10

4

Answer 11

try it like this, keeping track of the locations of the letters.

Answer 12

ok 90 degrees works

Answer 13

Forget the angles.

Answer 14

ok

Answer 15

Think about how you can rotate it, and keep it looking exactly the same.

Answer 16

ok i got the answer... it is 120 and 240 degrees

Answer 17

3?

Answer 18

That's once

Answer 19

twice

Answer 20

Three times.

What total angle did I rotate it through, to get it back to how it started?

Answer 21

360

Answer 22

Yep. So you rotated it through 360, and it took 3 rotations. So each angle of rotation must be?

Answer 23

120

Answer 24

Yep, or any multiple of 120.

Answer 25

so 60,12,240

Answer 26

*120

Answer 27

so the final answers are 60,120,240 right?

Answer 28

"any multiple of 120."

Answer 29

ok so yes

Answer 30

wait its just120 and 240