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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

21r

1r2

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)

1/31r2h

1r2+1rl

cylinder

1r2h

1r2+21rh

Pyramid (B = area of base)

1/3Bh

sphere

4/31r3

41r2


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