Maths year 11

Yeah, but remember I told you if you SPLIT the angle in Tile B, you get the exterior angle of Tile A.

Omg I get it.

Interior angles add up to 180.

So 180-150=30??

Posted from TSR Mobile

The interior + exterior = 180. Reason being because angles on a straight line add to 180.

The interior angles themselves don't add to 180, but the interior and exterior add to 180.

You're getting there

So if I split the triangle it will give me 30+150=180

And then?

Posted from TSR Mobile

Yep.
Now, take a look at the formula that you use to work out the exterior angle, as you mentioned it's 360/n.

Now that you have the ext. angle, you may be able to do something with the formula.

I don't get this!!!

Interior is on the inside.

Exterior is on the outside.

360/ number of sides .

Number of sides can't be 30.



Posted from TSR Mobile

No, look, 360/n=30 is what you have rn. You're looking for n, how would you find that?

360/30?

Posted from TSR Mobile

Yep!

Ohhh.
But why do I find half the triangle?



Posted from TSR Mobile

Ohhh.
But why do I find half the triangle?



Posted from TSR Mobile

I don't know if you've seen it in a revision guide but if you extend the line from a vertex of the polygon, you get a straight line and then if you subtract the int. angle from 180 you get the ext angle.

In this scenario, if you look closely, you'll realise that splitting the angle in the triangle actually gives you a straight line, making the splitted angle the exterior, does that make sense? I'm sorry if that was confusing

Yeah ill go over this tomorrow. Got a headache from this question.

Posted from TSR Mobile

You don't have to. You can use the fact that the angles add up to 360 degrees.

Haha, no worries, it's never good to stress over a question, cya

I got this far with this question


Posted from TSR Mobile

The line PE bisects the interior angle of the hexagon at HAB. Mark this angle EAB, then angle EAB + PAB add to 180 degrees.

I got this far with this question


Posted from TSR Mobile

So my calculations are wrong?

Posted from TSR Mobile

You got the sum of all the interior angles correct. Now work out how much each one is worth as there are 8 of them. This should give you angle HAB. Recognise that HAP=BAP=y degrees (not sure if you need to prove this). This should give you interior + 2y = 360 since you've pointed out that interior + exterior = 360; and you can solve for y.