Question

find the total surface area and lateral surface area of cuboid whose length breadth and hight is 20cm 15cm and 18cm.​

Answer 1

Given :-

• Length of cuboid = 20 cm
• Breadth of cuboid = 15 cm
• Height of cuboid = 18 cm

To find :-

1. Total Surface Area (TSA) = ?
2. Lateral Surface Area (LSA) = ?

Solution :-

TSA of cuboid = 2(lb + bh + hl)

⇒ TSA of cuboid = 2((20 × 15) + (15 × 18) + (18 × 20)

⇒ TSA of cuboid = 2(300 + 270 + 360)

⇒ TSA of cuboid = 2(930)

∴ TSA of cuboid = 1860 cm²

LSA of cuboid = 2(l + b)h

⇒ LSA of cuboid = 2(20 + 15)18

⇒ LSA of cuboid = 2(35) 18

⇒ LSA of cuboid = 70 × 18

∴ LSA of cuboid = 1260 cm²

Know more:

$\begin{array}{|c|c|c|}\cline{1-3}\bf Shape&\bf Volume\ formula&\bf TSA \: formula\\\cline{1-3}\sf Cube&\tt l^3}&\tt 6l^2\\\cline{1-3}\sf Cuboid&\tt lbh&\tt 2(lb+bh+lh)\\\cline{1-3}\sf Cylinder&\tt {\pi}r^2h&\tt 2\pi{r}(r+h)\\\cline{1-3}\sf Hollow\ cylinder&\tt \pi{h}(R^2-r^2)&\tt 2\pi{rh}+2\pi{Rh}+2\pi(R^2-r^2)\\\cline{1-3}\sf Cone&\tt 1/3\ \pi{r^2}h&\tt \pi{r}(r+s)\\\cline{1-3}\sf Sphere&\tt 4/3\ \pi{r}^3&\tt 4\pi{r}^2\\\cline{1-3}\sf Hemisphere&\tt 2/3\ \pi{r^3}&\tt 3\pi{r}^2\\\cline{1-3}\end{array}$

Answer 2

Answer:

Explanation:

Given:

length = 20 cm

breadth = 15 cm

height = 18cm.​

Total surface Area of cuboid =

2(lb + bh + hl)

= 2(20 x 15 + 15 x 18 + 18 x 20) 

= 2(300 + 270 + 360)

= 2 x 930  

= 1860 $cm^2$

Lateral surface area of a cuboid

= 2h(l + b)

= 2 x 18(20 + 15)

= 36 x 35  

= 1260 $cm^2$