Question

The sum of length breadth and height of a cuboidal room is 26 and length of its diagonal is 20 m . Find the tsa of cuboid.

Plz.. do step by step
Correct answer will be brainliest... worng answer will be reported ​

Answer 1

Answer:

TSA=276  m²

Step-by-step explanation:

let the sides of cuboidal are a,b and c

a+b+c=26

length of diagonal=√a²+b²+c²=20

so a²+b²+c²=400............(1)

(a+b+c)²=26²

a²+b²+c²+2(ab+bc+ca)=676

400+2(ab+bc+ca)=676

2(ab+bc+ca)=676-400=276

Now TSA=2(ab+bc+ca)=276

Thus TSA=276  m²

Answer 2

Step-by-step explanation:

A.T.Q

Sum of length, breadth, and height of a cuboidal room is 26m

l + b + h = 26m ___(1)

And length of it's diagonal is 20m

√l2+b2 +h2 = 20

Squaring on both sides we get

l² + b² + h² = (20)²

We have to find total surface area of Cuboid.

Means;

2 (lb + bh + hl) = ?

l² + b² + h² = (20)²

(l + b + h)² - 2(lb + bh + hl) = 400

(26)² - 2(lb + bh + hl) = 400 [from (1)]

676 - 2(lb + bh + hl) = 400

676 - 400 = 2(lb + bh + hl)

276 = 2(lb + bh + hl)

2(lb + bh + hl) = 276

So, the total surface area of Cuboid is 276m2

Hope this is helpful for you.