Shape 2 Facts Flashcards
How do you find the area of a parallelogram?
Base x perpendicular height
How do we find the area of a rectangle?
Length x width
How do we find the area of a triangle?
Half x base x perpendicular height
What is the formula for the area of a trapezium?
Half x (top + bottom) x height
Name two 2D shapes whose area formulae include dividing by 2.
Triangle and Trapezium
What’s the formula for the circumference of a circle?
πd or 2πr
What’s the formula for the area of a sector?
πr² x angle / 360
What’s the formula for the area of a circle?
πr²
What’s the formula for the length of an arc?
2πr x angle / 360
How do you find the area of a semi circle?
πr² ÷ 2
If you know the length of a radius of a circle, how do you find the diameter?
Double the radius
What do we call the straight line across a circle that does not go through the centre?
Chord
What do we call the part of a circle between a chord and the circumference?
Segment
What do we call the part of a circle between two radii and the circumference
Sector
What do we call the straight line that touches a curve at a point but doesn’t cross it?
Tangent
Complete the circle theorem: “The angle in a semi circle is …”
A right angle
Complete the circle theorem: “The perpendicular from the centre of a circle to a chord….”
Bisects the chord
Complete the circle theorem: ‘a radius meets a tangent at…’
A right angle
Complete the circle theorem: ‘Opposite angles in a cyclic quadrilateral…’
Sum to 180 degrees
Complete the circle theorem: ‘The angle at the centre is …”
Twice the angle at the circumference.
Name the circle theorem which has a triangle and a tangent with a circle
Alternate segment theorem
What’s the name for a quadrilateral which has all four vertices touching the circumference of a circle?
Cyclic quadrilateral
Are bearings measured clockwise or antclockwise?
Clockwise
From which compass direction are bearings measured?
North
How many figures must a bearing be?
3
When measuring a bearing of A from B where is the centre of the protractor placed?
On B
If the bearing of A from B is 110, what is the bearing of B from 8
110 + 180 = 290
Which regular shapes tessellate?
Squares, equilateral triangles and regular hexagons.
What is tessellation?
Shapes fitting together with no gaps between them.
When regular hexagons tessellate how many meet at a point?
3
When squares tessellate how many meet at a point?
4
Why don’t regular pentagons tessellate?
No multiple of their interior angle equals 360 degrees
If the length scale factor is k, what is the volume scale factor?
k³
If the length scale factor is k, what is the area scale factor?
k²
If the volume scale factor is t³, what is the area scale factor?
t²
If the volume scale factor is t³, what is the length scale factor?
t
If the volume scale factor is a, what is the length scale factor?
Cube root of a
If the area scale factor is a, what is the length scale factor?
√a
How do you find the volume of a cube with side length x?
x³
How do you find the volume of a cuboid?
Length x width x height
How do you find the volume of a cylinder with height h and radius r?
πr²h
How do you find the volume of a prism?
The area of the cross section multiplied by the height
What is the formula for the curved surface area of a cylinder with height h and radius r?
2πrh
How do you find the volume of a cone with height h and radius r?
A third x πr²h
How do you find the surface area of a cuboid with length a, width b and height c?
2(ab + ac + bc)
