50points..clear explanation needed
Answers
Given that side of each cube is √7 cm.
●Then area of each face of cube = (√7)² = 7 cm²
Now, 6 of the cubes are attached to six faces of 7th to make a toy. Which means 7th cube is completely flanked by 6 cubes ouside. So 7th cube doesn't contribute to TSA.
And one face of each of 6 cubes is attached to inner cube. So one face of each of 6 cubes doesn't contribute to Surface area.
So, among six faces only five faces contribute to TSA. And there are such 6 cubes.
Hence,
● number of faces, contributing TSA = 5
●Number of such cubes = 6
TSA = Area of one face × number of face contributing TSA × Number of such cubes.
TSA = 7 × 5 × 6 = 210 cm².
Answer:
210 cm²
Step-by-step explanation:
a toy is made with seven equal cubes of sides root 7 cm. Six cubes are joined to six faces of a seventh cube. Find the total surface area of the toy
Surface Area of a cube = 6 * side² = 6 * (√7)² = 42 cm²
Surface Area of one side of a cube = side² = (√7)² = 7 cm²
When six cubes joined to six faces of 7th cube
then 5 faces of 6 cubes are available
so total surface area of toy = 6 * 5 * side²
= 6 * 5 * (√7)²
= 210 cm²
or we can say surface area of 7 cubes = 7 * 42 = 294 cm²
six faces are joined together with other six faces
so 12 faces are reduced
area of 12 faces = 12 * 7 = 84 cm²
Area of toy = 294 - 84 = 210 cm²