Mensuration Practice Test 2

Volume of new cubes = Sum of volume of three cubes
= A + B + C
= ${\left(6\right)}^3+{\left(8\right)}^3+{\left(10\right)}^3$
= 216 + 512 + 1,000
= 1,728
Side of cube = $\sqrt[3]{\left(1728\right)}$
= 12 cm.
Diagonal of the cube = d = $\sqrt{3}$ a
= $\sqrt{3}$ . 12
= 1.73 × 12 = 20.8 cm.