Question

HELP PLEASE... my graduation depends on this...

A source of laser light sends rays AB and AC toward two opposite walls of a hall. The light rays strike the walls at points B and C, as shown below

Answer 1

What is the distance between the walls?
Answer 50 m
70 m
100 m
110 m

Answer 2

Use \(\cos60^\circ=\frac{80}{X}\) to find the right length.
Use \(\tan 45^\circ=\frac{30}{A}\) to find the left length.

Ad them up.

Answer 3

ohh wow GOOD LUCK THEN

Answer 4

some how i got this -364

Answer 5

Oops, sorry an error (though it definitely wouldn't make your number negative).
\[cos 60^\circ=\frac{X}{80}\]

Answer 6

do i multiply 80 to both sides

Answer 7

Correct. So do cos 60 * 80 = X

Answer 8

cos(60)80?

Answer 9

Yes

Answer 10

i got -76.19303843

Answer 11

You should check your calculator to make sure it's in degrees mode.

For example, try this query in Google:
(80*cos 60 degrees)+(30/tan 45 degrees)

Answer 12

oh ok, it was the calculator. i got 40 now. thanks i can take it from here