Question

Can someone help me please!? I'll give a medal.

Find the value of x. Round the answer to the nearest tenth, if needed.
A.6.9
B.15.9
C.36.8
D.42.3

Answer 1

Anyone know the formula, or how to set this equation up?

Answer 2

Well, let's see.

x^2 + 12^2 = C^2
x^2 + 21^2 = D^2
C^2 + D^2 = (33)^2

That's three equations in three unknowns. It should be possible to solve it.

Answer 3

I'm sorry I don't understand.. I don't know how to get the answer from that.

Answer 4

Solve the simultaneous equations:

From C^2 + D^2 = (33)^2 [this is the Pythagorean theorem applied to the big triangle]

get

C^2 = (33)^2 - D^2

Answer 5

In x^2 + 12^2 = C^2 [this is the small triangle on the right, Pythagorean theorem)

substitute

C^2 = (33)^2 - D^2

Answer 6

Okay, thank you I will try it.

Answer 7

I'm getting b.

Answer 8

I am getting \[x=\sqrt{945-D^2}\]

Answer 9

So, yes. I think it's B.

Answer 10

When you use

\(\huge x^2 + 21^2 = D^2 \)

you get

\( \huge x^2 = 945 -x^2 - 21^2 \)

\( \huge 2x^2 = 504 \)

\(\huge x^2 = \sqrt{252} \approx 15.87 \)