232,123 views
17 votes
17 votes
The triangular faces of the prism shown are equilateral triangles with perimeter 30 cm. Use a net to find the surface area of the prism.

The triangular faces of the prism shown are equilateral triangles with perimeter 30 cm-example-1
User Tcak
by
3.0k points

1 Answer

16 votes
16 votes

Step-by-step explanation:


\begin{gathered} The\text{ surface area is made up of the two equilateral triangles shown above as well as the three rectangles.} \\ Area\text{ of Triangles = 2\lparen}(1)/(2)b*h) \\ If\text{ the perimeter of the triangle is 30cm, the length of one side = 30/3 = 10 = base} \\ Area\text{ = 2\lparen}(1)/(2)*10*8.7) \\ \text{ =87} \\ Area\text{ of the three rectangles = 3\lparen length*width\rparen } \\ \text{ =3\lparen10*12\rparen} \\ \text{ =360} \\ Total\text{ Surface Area = 360 + 87 = 447} \end{gathered}

Surface Area of the two triangles in the net = 2*(0.5*b*h)

= 2*(0.5*10*8.7)

=87

Surface Area of three rectangles in the net = 3(l*b)

= 3*12*10

=360

Answer: Total Surface area = 360 + 87 = 447

The triangular faces of the prism shown are equilateral triangles with perimeter 30 cm-example-1
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.