contestada

the base of a right prism is a rhombus whose diagonals are 6 in and 8. If the altitude of the prism is 12, what is the total surface area of the prism?

Respuesta :

Answer:

The total surface area of the prism is [tex]SA=288\ in^{2}[/tex]

Step-by-step explanation:

we know that

The two diagonals of a rhombus are perpendicular and bisect each other

All sides are congruent

The surface area of a prism is equal to

[tex]SA=2B+Ph[/tex]

where

B is the area of the base of prism

P is the perimeter of the base of prism

h is the height of the prism

step 1

Find the length side of the rhombus

Applying Pythagoras Theorem

[tex]c^{2}=a^{2}+b^{2}[/tex]

we have

c is the length side of the rhombus

a and b are the semi diagonals of the rhombus

[tex]a=8/2=4\ in[/tex]

[tex]b=6/2=3\ in[/tex]

substitute

[tex]c^{2}=4^{2}+3^{2}[/tex]

[tex]c^{2}=25[/tex]

[tex]c=5\ in[/tex]

step 2

Find the perimeter of the base P

The perimeter of the rhombus is equal to

[tex]P=4c[/tex]

[tex]P=4(5)=20\ in[/tex]

step 3

Find the area of the base B

The area of the rhombus is

[tex]B=\frac{1}{2}[D1*D2][/tex]

D1 and D2 are the diagonals of the rhombus

substitute

[tex]B=\frac{1}{2}[8*6]=24\ in^{2}[/tex]

step 3

Find the surface area of the prism

[tex]SA=2B+Ph[/tex]

substitute the values

[tex]SA=2(24)+(20)(12)[/tex]

[tex]SA=288\ in^{2}[/tex]