Question

What is the length of stack D F with bar on top in the rectangular prism? Round to the nearest tenth of a centimeter.



A.
15.3 cm

B.
14.6 cm

C.
13.0 cm

D.
10.2 cm

Answer 1

How do you do this?

Answer 2

We know that:
GF = EH = 5
HG = EF = 12

Use Pythagorus Theorem to calculate:HF

Answer 3

(12)^2 + (5)^2 = HF = ?

Answer 4

Oops I made a mistake

HF = \[\sqrt{(12^2) + (5^2)}\]

Answer 5

13

Answer 6

Once we find this length HF we can use it to find DF by:

DH^2 + HF^2 = DF^2

Answer 7

Yes,now that we its 13 ,we can move on to the next part.

We know that:
DH = 8 cm
HF = 13 cm (calculated)
DH^2 + HF^2 = DF^2

Answer 8

so square root of 233 will = the answer?

Answer 9

Yes,
\[\sqrt{233} = ?\]

Answer 10

15.264

Answer 11

nearest tenth
15.3

Answer 12

Yes,we can re-write 15.264 as 15.3 cm

Answer 13

CORRECT!

Answer 14

I am going to have to review that question again haha.
Thanks! :)

Answer 15

Its basically Pythagorus Theorem Ive used here.
Look at the diagram carefully.

Answer 16

When we first look at the problem we can clearly see an right angled triangle DHF.
One side is given as 8 cm
And the other are missing/have to be calculated.

Now look at the base of the diagram.Its a Rectangle.
The opposite of a rectangle are equal.
SO if,
EF = 12 then HG = 12
GF = 5 then EH = 5

Answer 17

Now we have two know sides for the buttom triangle and we have to calculate the 3rd missing side using Pythagorus Theorem.

Answer 18

Once we find that we come back to the second triangle whose one side is given as 8 cm and the second side calculated as above then again we use Pythagorus Theorem,to find the DF(the missing length asked for).

Answer 19

Okay. I get it now.
Thanks! :)