Question

3. ) A rectangular prism measures 10 cm by 7 cm by 3 cm, what is the surface
area?
A 302 cm²
B. 245 cm²
C. 242 cm²
D.200 cm²
​

Answer 1

Answer:

(c) 242 cm²

Step-by-step explanation:

A rectangular prism measures 10 cm by 7 cm by 3 cm.

∴ The surface area is = [2 × (10 × 7) + 2 × (10 × 3) + 2 × (7 × 3)] = 242 cm²

Answer 2

Answer:

♢ Surface area of the prism = 242 cm².

SOLUTION

Length of the rectangular prism = 10cm.

Breadth of the rectangular prism = 7cm.

Height of the rectangular prism = 3cm.

The rectangular prism is actually in the shape of a cuboid.

TSA

Total Surface Area (TSA) of a cuboid = 2(lb + bh + lh) , Where l is the length , b is the breadth and h is the height of the cuboid.

Here ,

l = 10cm.

b = 7cm.

h = 3cm.

⇒ TSA of the cuboid = 2(10×7 + 7×3 + 10×3)

⇒ TSA of the cuboid = 2(70 + 21 + 30)

⇒ TSA of the cuboid = 2 × 121

⇒ TSA of the cuboid = 242 cm².

LSA

Lateral surface area (LSA) of a cuboid = 2(l + b) × h , Where l is the length , b is the breadth and h is the height of the cuboid.

Here ,

l = 10cm.

b = 7cm.

h = 3cm.

⇒ LSA of the cuboid = 2( 10 + 7) × 3

⇒ LSA of the cuboid = 2 × 17 × 3

⇒  LSA of the cuboid = 102 cm²