Question

In figure 5.47, the value of cosΦ is:
I know answer. Please explain it ​

Answer 1

ANSWER :- 54°

HOPE THE GIVEN ATTACHMENT HELPS U

♡FOLLOW

THANKS ❤

Answer 2

Given :  A figure showing two right angle triangles whose hypotenuse are at right anglr too

To find : value of cosΦ

Solution:

ECB is a straight line

Hence ∠ECD  + ∠DCA + ∠ACB  = 180°

=> Ф  + 90° + θ = 180°

=>  Ф  + θ = 90°

in ΔABC

∠ABC = 90°

∠ACB = θ

& ∠CAB = 180° - 90° - θ  = 90° - θ  = Ф

CosФ = cos ∠CAB = AB/AC = 4/5 = 0.8

or

in ΔCED

∠CED = 90°

∠CDE = 180° - 90° - Ф  = 90° - Ф = θ

∠ECD = Ф

=>  ΔABC  ≈  ΔCED

=> AB/CE = AC/CD  = BC/DE

=> AB/AC  = CE/CD

cosΦ  = CE/CD  =  AB/AC  =   4/5

=> cosΦ  = 0.8

Learn more:

in a right angle triangle ABC angle is equal to 90 degree and 5 sin ...

https://brainly.in/question/8717787

In the diagram, given below,triangle ABC is right-angled at B and BD ...

https://brainly.in/question/2737587