Surprise!

Try out some calculations. Are you surprised by the results?

Draw some angles inside a rectangle. What do you notice? Can you prove it?

Take any four digit number. Move the first digit to the end and move the rest along. Now add your two numbers. Did you get a multiple of 11?

Can you work out the fraction of the original triangle that is covered by the inner triangle?

Do you have enough information to work out the area of the shaded quadrilateral?

Can you work out the fraction of the original triangle that is covered by the green triangle?