Find the area $A$ of a triangular prism if length $l = 12 cm$ and height $h = 7.8 cm$ .

Answer

$394.4919 cm^{2}$

Explanation

STEP 1: find side $a$

To find side $a$ use formula:

h = \frac{3 \cdot a}{2}

After substituting $h = 7.8 cm$ we have:

7.8 cm = \frac{3 \cdot a}{2}

3 \cdot a = 7.8 cm \cdot 2

3 \cdot a = 15.6 cm

a = \frac{15.6 cm}{3}

a \approx 9.0067 cm

STEP 2: find area $A$

To find area $A$ use formula:

A = \frac{a ^{2} 3}{2} + 3 a l

After substituting $a = 9.0067 cm$ and $l = 12 cm$ we have:

A = \frac{9.0067 cm ^{2} 3}{2} + 3 \cdot 9.0067 cm \cdot 12 cm

A = \frac{81.12 cm ^{2} 3}{2} + 3 \cdot 108.08 cm^{2}

A = \frac{140.504 cm ^{2}}{2} + 324.2399 cm^{2}

A = 70.252 cm^{2} + 324.2399 cm^{2}

A = 394.4919 cm^{2}

This page was created using

Triangular Prism Calculator

About the Author

Welcome to MathPortal. This website's owner is mathematician Miloš Petrović. I designed this website and wrote all the calculators, lessons, and formulas.

If you want to contact me, probably have some questions, write me using the contact form or email me on mathhelp@mathportal.org.

Send Me A Comment

Main Navigation

Online Math Calculators

Find the area A of a triangular prism if length l=12cm and height h=7.8cm.

394.4919cm2

Find the area $A$ of a triangular prism if length $l = 12 cm$ and height $h = 7.8 cm$ .

$394.4919 cm^{2}$