there is a room 7 feet x 9 feet you lay a 1-foot wide plank from corner to corner touching all 4 walls how long is the plank

Step-by-step explanation:

l^2=[(7-V2)/2]^2+(9-V2/2)^2=

49-7V2+2/4+81-9V2+2/4=

49+81+4/4-16V2=

131-16V2=108.4 ft

so l=V108.4≈10.4ft

the correct option is 2.

step-by-step explanation:

according to the given information triangle abc is a right angle triangle with right angle at a. segment ab is 5 and segment ac is 7. point d is on segment bc and angles adb and adc are right angles.

it is given that triangles abd, cad, and cba are similar.

two triangles are similar if their corresponding sides are proportional.

in triangle cba, using pythagoras theorem

                      )

triangle abd and cba are similar,

                            (2)

triangle cad and cba are similar,

                      )

using (1), (2) and (3), we get

hence proved.

therefore option 2 is correct.

answer: what are the answer choices?

step-by-step explanation: