Geometry Flashcards
(29 cards)
what is the formula to calculate the area of a circle?
A=πx r²
what do angles around a point add up to?
angles round a point add up to 360˚
what is the volume of a cuboid
V=L x W x H
area of a trapezium
A=1/2 (a+b) x h
what is perimeter
perimeter is the distance all the way around the outside of a 2D shape.
circumference of a circle?
C= π x D
C=2 x π x r
what do interior angles in a quadrilateral add up to?
a +b+ c + d = 360˚
how do you find the perimeter of a shape
Add up all the lengths of the side
acute angles?
less than 90˚ - sharp pointy ones!
what are faces
the flat bits
what do interior angles in a triangle add up to?
a +b+ c= 180˚
what are edges
the edges are the edges!
what would you do to find the area of a complicated shape
break it down in to smaller simpler shapes that you know the formula for
what do angles on a straight line add up to?
angles on a straight line add up to 180
what are the properties of a square
4 equal angels of 90 (right angles)
4 lines of symmetry
rotational symmetry
diagonal cross symmetry
whas is pythagoras’ theoram
a² + b² = c²
what are vertices
corners
right angles?
exactly 90˚ - square corners
area of a parallelogram
A=b x h
what is the volume of a triangular prism
V=A x L
Volume + cross sectional area x height
what is the exterior angles of a triangle
= sum of opposite interior angles
a+b=d
describe the diameter of a circle
Diameter goes right across the circle passing through the centre
The diameter is exactly double the radius
Obtuse angles?
Between 90˚ and 180˚ - flatter ones
what is a prism
A prism is a solid 3D object which is the same shape all the way through i.e. it has a constant area of cross section.
If you cut it all the slices would be the same
