Mensuration
Figure            Area               Perimeter                          Diagonal
   Square              a2                    4a                              √2𝑎
  Rectangle          𝑙 ×𝑏               2 ( (𝑙 × 𝑏 )                      √𝑙 2 × 𝑏 2
Rectangle of    2𝑥(𝑙+𝑏−2𝑥)             4 ( 𝑙 + 𝑏 − 2𝑥)                         -
path inside
Rectangle of    2𝑥 ( 𝑙 + 𝑏 + 2𝑥)       4 ( 𝑙 + 𝑏 + 2𝑥)                         -
path outside
Rectangle of     𝑥(𝑙+𝑏−𝑥)              2 ( 𝑙 + 𝑏 − 2𝑥)                         -
path midway
                  𝒍𝒆𝒏𝒈𝒉𝒕 𝒐𝒇 𝒐𝒏𝒆 𝒅𝒊𝒂𝒈𝒐𝒏𝒂𝒍 𝒂𝒓𝒆𝒂 = 𝟐√𝒔(𝒔 − 𝒂 )(𝒔 − 𝒃)(𝒔 − 𝒅)
Parallelogram
                𝑏𝑎𝑠𝑒 × ℎ𝑒𝑖𝑔ℎ𝑡        2 (𝑎 + 𝑏 )                𝑑12 + 𝑑 22 = 2 ( 𝑎2 + 𝑏2 )
  Rhombus           1                4𝑎 (𝑜𝑟) 4𝑎2 = 𝑑12 + 𝑑22
                      𝑑 𝑑
                    2 1 2
Trapezium      1                      𝑎+𝑏+𝑐+𝑑                  𝑑12 + 𝑑22 = 𝑐 2 + 𝑑2 + 2𝑎𝑏
                 (𝑎+𝑏)×ℎ
               2
 Triangle        1                   𝑠𝑒𝑚𝑖 𝑝𝑒𝑟𝑖𝑚𝑒𝑡𝑒𝑟          𝒊𝒏𝒄𝒊𝒓𝒄𝒍𝒆           𝑐𝑖𝑟𝑐𝑢𝑚𝑟𝑎𝑑𝑖𝑢𝑠
                   𝑏𝑎𝑠𝑒                   𝑎+𝑏+𝑐             𝑎𝑟𝑒𝑎 𝑜𝑓 ∆                   𝑎𝑏𝑐
                 2
                 × ℎ𝑒𝑖𝑔ℎ𝑡             𝑠=                                       𝑅=
                                              2           𝑠𝑒𝑚𝑖 𝑝𝑒𝑟𝑖𝑚𝑒𝑡𝑒𝑟           4 × 𝑎𝑟𝑒𝑎 𝑜𝑓 ∆
 Isosceles      1                        2𝑎 + 𝑏                               √4𝑎 2 − 𝑏2
                  ×𝑏                                               ℎ𝑒𝑖𝑔ℎ𝑡 =
  triangle      2                                                                  2
                  √4𝑎2 − 𝑏2
                ×
                      2
Equilateral        √3 2                  𝑠 = 3𝑎           ℎ𝑒𝑖𝑔ℎ𝑡     𝑖𝑛𝑟𝑎𝑑𝑖𝑢𝑠    𝑐𝑖𝑟𝑐𝑢𝑚𝑟𝑎𝑑𝑖𝑢𝑠
 triangle             𝑎                                                  𝑎     ℎ     𝑎
                    4                                        √3𝑎     =      𝑜𝑟   =
                                                          =                    3    √3
                                                              2         2√3
                                       √𝟑         𝒂
                      𝑷𝟏 + 𝑷𝟐 + 𝑷𝟑 =      𝑶𝑹 𝒂 =    ( 𝑷𝟏 + 𝑷𝟐 + 𝑷𝟑 )
                                        𝒂        √𝟑
Right angle   1                        𝑃+𝐵+𝐻            𝑖𝑛𝑟𝑎𝑑𝑖𝑢𝑠 𝑐𝑖𝑟𝑐𝑙𝑒
                𝑝𝑒𝑟𝑝𝑒𝑛𝑑𝑖𝑐𝑢𝑙𝑎𝑟
 triangle     2                                            𝑃+𝐵−𝐻
              × 𝑏𝑎𝑠𝑒                                    =
                                                               2
 CIRCLE                    𝜋𝑑 2       2𝜋𝑟 (𝑜𝑟 )𝜋𝑑
               𝜋𝑟 2 (𝑜𝑟)
                            4
Semi circle
                    𝜋𝑟 2                                  𝑐𝑖𝑟𝑐𝑢𝑚𝑓𝑒𝑟𝑒𝑛𝑐𝑒 = 𝜋𝑟 + 𝑑 (𝑜𝑟) 𝜋𝑟 + 2𝑟
                     2
 Sector of                  𝜃           𝐴𝐶 + 𝐴𝐵 + 2 𝑟              𝑙𝑒𝑛𝑔𝑡ℎ 𝑜𝑓 𝑠𝑒𝑐𝑡𝑜𝑟 = 𝐴𝐶𝐴𝐵
                𝜋𝑟 2 ×
  circle                   360               (𝑜𝑟)                                       𝜃
                                                                                 = 2𝜋𝑟
                                            𝑙 + 2𝑟                                     360
   Cube             4𝑎2           𝑡𝑜𝑡𝑎𝑙 𝑠𝑢𝑟𝑓𝑎𝑐𝑒 𝑜𝑓 𝑎𝑟𝑒𝑎        𝑑𝑖𝑎𝑔𝑜𝑛𝑎𝑙 𝑜𝑓 𝑐𝑢𝑏𝑒 = √3𝑎
                                                 = 6𝑎2
                                                            𝑓𝑎𝑐𝑒 𝑜𝑓 𝑑𝑖𝑎𝑔𝑜𝑛𝑎𝑙 𝑜𝑓 𝑐𝑢𝑏𝑒 = √2𝑎
                                                                   𝑣𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑐𝑢𝑏𝑒 = 𝑎3
  Cuboid        𝑣𝑜𝑙𝑢𝑚𝑒            𝑙𝑎𝑡𝑒𝑟𝑎𝑙 𝑠𝑢𝑟𝑓𝑎𝑐𝑒 𝑎𝑟𝑒𝑎          𝑠𝑢𝑟𝑓𝑎𝑐𝑒 𝑎𝑟𝑒𝑎 𝑜𝑓 𝑐𝑢𝑏𝑜𝑖𝑑
                =𝑙 ×𝑏 ×ℎ             = 2(𝑙+𝑏)×ℎ                   = 2 ( 𝑙𝑏 + 𝑏ℎ + 𝑙ℎ )
                                                   𝑑𝑖𝑎𝑔𝑜𝑛𝑎𝑙 𝑜𝑓 𝑐𝑢𝑏𝑜𝑖𝑑𝑑 = √𝑙 2 + 𝑏2 + ℎ 2
Cylinder   𝑣𝑜𝑙𝑢𝑚𝑒 = 𝜋𝑟 2 ℎ   𝑐𝑢𝑟𝑣𝑒𝑑 𝑠𝑢𝑟𝑓𝑎𝑐𝑒 𝑎𝑟𝑒𝑎            𝑡𝑜𝑡𝑎𝑙 𝑠𝑢𝑟𝑓𝑎𝑐𝑒 𝑎𝑟𝑒𝑎
                                          = 2𝜋𝑟ℎ             = 2𝜋𝑟ℎ + 2𝜋𝑟 2 ℎ
                                                                    𝑜𝑟
                                                                2𝜋𝑟 (𝑟 + ℎ)
 Cone      𝑣𝑜𝑙𝑢𝑚𝑒 =          𝑐𝑢𝑟𝑣𝑒𝑑 𝑠𝑢𝑟𝑓𝑎𝑐𝑒 𝑎𝑟𝑒𝑎            𝑡𝑜𝑡𝑎𝑙 𝑠𝑢𝑟𝑓𝑎𝑐𝑒 𝑎𝑟𝑒𝑎
           1
             𝜋𝑟 2 ℎ                 = 𝜋 𝑟𝑙                     = 𝜋𝑟𝑙 + 𝜋𝑟 2
           3
                                                                     𝑜𝑟
                                                                 𝜋𝑟 (𝑟 + 𝑙)
                               𝑠𝑙𝑎𝑛𝑡 ℎ𝑒𝑖𝑔ℎ𝑡 = 𝐿
                               = √𝑅2 + ℎ 2