Question

The Pyraminx is a Rubik’s cube-toy in the shape of a tetrahedron. The Pyraminx shown below has edges of 15cm long and a vertical height h=12.2 cm. The Triangle drawn with dashed lines is a right triangle. What is distance r?

Answer 1

Answer:

The distance r is $8.7\ cm$

Step-by-step explanation:

we know that

Applying the Pythagoras Theorem

$c^{2}=a^{2}+b^{2}$

where

c is the hypotenuse

a,b are the legs

In this problem we have

$c=15\ cm$

$a=r$

$b=h=12.2\ cm$

substitute and solve for r

$15^{2}=r^{2}+12.2^{2}$

$225=r^{2}+148.84$

$r^{2}=225-148.84$

$r^{2}=76.16$

$r=8.7\ cm$