Question

In △RST, what is the length of RT?

Answer 1

Use cosine, which is Adjacent over Hypotenuse.

\[\cos 45 = \frac{36}{RT}\]
\[RT=50.9116882\]

Answer 2

Alternatively, since the triangle is 45 degrees on both arms, then you can just assume that the second arm is the same as the first arm, and then use Pythagorean's theorem to get the same answer.
\[a^2+b^2=c^2\]
\[2a^2=c^2\]
\[2(36)^2=c^2\]
\[\sqrt{2592}=50.9116882....\]

Answer 3

oh ok, so RT would be 36 sqrt 2 right?

Answer 4

Correct.