IDNLearn.com makes it easy to find precise answers to your specific questions. Our platform provides prompt, accurate answers from experts ready to assist you with any question you may have.

what is the surface area of triangular pyramid?​

What Is The Surface Area Of Triangular Pyramid class=

Sagot :

Answer:

223.5 in²

Step-by-step explanation:

The surface area of a triangular pyramid comprises:

  • Area of the base triangle.
  • Area of 3 congruent side triangles.

Area of a triangle

[tex]\sf A=\dfrac{1}{2}bh[/tex]

where:

  • b = base
  • h = height

From inspection of the diagram:

  • Base triangle:  b = 10 in,  h = 8.7 in
  • Side triangles:  b = 20 in,  h = 12 in

[tex]\begin{aligned}\implies \textsf{Area of the base triangle} & = \sf \dfrac{1}{2} \cdot 10 \cdot 8.7\\& = \sf 5 \cdot 8.7\\& =\sf 43.5\:in^2\end{aligned}[/tex]

[tex]\begin{aligned}\implies \textsf{Area of a side triangle} & = \sf \dfrac{1}{2} \cdot 10 \cdot 12\\& = \sf 5 \cdot 12\\& =\sf 60\:in^2\end{aligned}[/tex]

[tex]\begin{aligned}\implies \textsf{S.A. of the triangular pyramid} & = \textsf{base triangle}+\textsf{3 side triangles}\\& = \sf 43.5 + 3(60)\\& = \sf 43.5 + 180\\& = \sf 223.5\:in^2\end{aligned}[/tex]

Therefore, the surface area of the given triangular pyramid is 223.5 in².