Question

Answer this question. please​

Answer 1

Answer: 46cm²

-The cuboid has 4 equal rectangles and 2 equal square sides .

- To find the total surface are find the area of 1 rectangle and multiply by 4 than find the area of one square and multiply by 2.

The area of the rectangle is already given : 7cm²

Area of 4 rectangle s= 7 × 4 = 28 cm²

Volume(V) of cuboid: 21 cm³

V = length × width × height(h)

21 =7 × 1 × h

21 = 7h

h = 21/7

h = 3 cm

Area of 2 squares = 2 × 3²

= 2 × 9

= 18 cm²

- Add the two values together to have your final answer .

Total Surface Area = 28 + 18

= 46 cm²

Answer 2

`\boxed{\textsf{ The total surface area of the cuboid is \textbf{62 cm} $\sf ^2$ .}}`

Explanation:

Given that the base area of the cuboid is 7cm² . And it's volume is 21cm³ . We need to find its total surface area . Now here we need to find the height . We can find height as ,

Height :-

`\qquad\boxed{\boxed{\sf Height =( Volume)/(Area ) }}`

`\sf\implies Height =(Volume)/(Area) \\\\\sf\implies h =( 21cm^3)/(7cm^2)\\\\\implies \boxed{ \pink{\frak { Height = 3 cm.}}}`

`\rule{200}2`

Let's find out the Total surface area .

TSA of cuboid :-

`\qquad\boxed{\boxed{\sf TSA_((cuboid)) =2(lb + bh + hl ) }}`

Put on the respective values :-

`\sf\implies TSA_((cuboid))= 2( lb + bh + hl )\\\\\sf\implies TSA_((cuboid))= 2( 7cm* 1cm + 1cm* 3cm + 3cm * 7 cm ) \\\\\sf\implies TSA_((cuboid))=2 ( 7cm ^2+3cm^2+21cm^2 ) \\\\\sf\implies TSA_((cuboid))= 2* 31cm^2 \\\\\sf\implies \boxed{\pink{\frak{ TSA_((cuboid))= 62 cm^2}}}`