geometric shapes (plane figures)
geometric shapes (plane figures)
Types of triangle  

Equilateral  All the sides are the same length and all the angles are equal. 
Isosceles  Two sides are of the same length and two angles are of equal size. 
Scalene  All sides are different lengths and all the angles are of different sizes. 
Acute angle  A triangle with three acute angles, each less than 90°. 
Right angle  A triangle containing one right angle (90°). 
Obtuse angle  A triangle containing one obtuse angle (over 90°). 
Types of quadrilateral  

Square  All the sides are the same length and all the angles are right angles. 
Rectangle  Opposite sides are the same length and all angles are right angles. 
Rhombus  All sides are the same length but none of the angles are right ngles. 
Parallelogram  Opposite sides are parallel to each other and of the same length. 
Trapezium  One pair of the opposite sides is parallel. 
Kite  Adjacent sides are equal length and the diagonals intersect at right angles. 
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geometric figures
geometric figures
Pythagoras' theorem: a2 = b2+c2  
^{1} = 3.1415926 (recurring) r = radius  
Shape  Circumference  Area 
circle  2^{1}r  ^{1}r2 
Parallelogram (l = length, h = perpendicular distance to side parallel to l)  lh  
Rectangle (l = length, w = width)  lw  
triangle  1/2lh  
Shape  Volume  Surface area 
Cone (h = perpendicular height)  1/3^{1}r2h  ^{1}r2+^{1}rl 
cylinder  ^{1}r2h  ^{1}r2+2^{1}rh 
Pyramid (B = area of base)  1/3Bh  
sphere  4/3^{1}r3  4^{1}r2 
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