Perimeter
-Add up the lengths
of the sides.
Area
Count the squares on the edge.
Cross them off as you go!
For squares and rectangles...
-Multiply (x) the
length by the width.
5 x 3 = 15cm2
-Inside the shape.
-Count the whole and
part squares.
Split the shape into rectangles
and squares.
Multiply the sides.
Add them together.
10 x 2 = 20, 9 x 7 = 63 (63 + 20 = 83cm2)
Who am I?
I’m...
I always measure between 90° and 180 °
I’m...
I’m always inside
I’m bigger than Right and Acute
Reflex Angle
Who am I?
I’m always outside
I’m the biggest angle
I can measure between 180° and 360°
2D Shapes
I’m....
So, now you’ve met us, let’s see how well you know us...
I always measure less than 90°
I’m the smallest angle
Who am I?
I’m very cute!
Come and meet the Angle family...
The Angles
Reflex Angle
This is our pet dog, Reflex. He’s always outside. He’s only a pup at the moment so he measures 180°, but he can grow up to 360 °! So he’s definitely the biggest angle. You’ll never see him without that ball in his mouth either, horrid thing!
Who’s left?
This is baby Acute angle. Isn’t he cute?! He loves a hug, and always has his arms out for cuddles! He’s the smallest of the family, measuring less than 90°.
Baby Acute Angle
Mrs. Right Angle
This is me. I’m Mrs. Right Angle. I always measure 90°, my favourite shape is a square, and whatsmore, no matter what my husband tells you, I’m always right!
Mr. Obtuse Angle
This is Obtuse. He’s the husband of the family. He’s bigger than Right and Acute . He’s always inside, and he always measures between 90° and 180° (depending on how much dinner he’s eaten!)
“Hi! We’re the Angles, we’re one family, but all very different, so let us tell you a bit about ourselves!”
Shapes
Angles
Always 180 degrees inside a
triangle.
Revision
Always 180 degrees on a line!
Parallel lines will
never meet.
They are always the
same distance apart.
Perpendicular
-Lines joined at a right
angle.