Question

The height of a triangular prism is 10 cm.The sides of the base are 3cm,4cm,5cm.find its total surface area

Answer 1

Given:

Height of triangular prism = 10 cm

Sides of base = 3, 4, 5 cm

To find:

Total surface area of prism = ?

Solution:

First of all, let us have a look at the formula for Total Surface Area of triangular prism:

$TSA = B + p\times h$

Where B is the area of base

p is the perimeter of base and

h is the height of prism.

here base is a right angled triangle (because 3, 4, 5 is a triplet) Base and Height will be 3 , 4 cm or 4, 3 cm and 5 will be hypotenuse.

So formula for B:

$B = \dfrac{1}{2}\times Base \times Height\\B = \dfrac{1}{2}\times 3\times 4 = 6 cm^2$

So, TSA = 6 + (3+4+5) $\times$ 10 = 6 + 120 = 126 $cm^2$

So, total surface area of given prism is 126$cm^2$.

Answer 2

TOTAL SURFACE AREA =LSA+2 AREA OF TRIANGLE