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