Answer :
- EF = 7.79423 feet or approximately 7.80 feet.
Solution :
As, we are given :
- ∆ABC ≅ ∆DEF
- AB = 4.5 feet
- AC = 9 feet
- ∠B = 90° ( from diagram)
- ∠E = 90° (from diagram)
We have to find :
As, we have ∆ABC ≅ ∆DEF, thus all corresponding sides and angles are equals.
- AB = DE = 4.5 feet
- BC = EF
- AC = DF = 9 feet
- ∠A = ∠D
- ∠B = ∠E = 90°
- ∠C = ∠F
Now, in ∆DEF, we have
- DE = 4.5 feet
- DF = 9 feet
- ∠E = 90°
So, we can find the side EF by using Pythagoras theorem, which is :
- (Hypotenuse)² = (Base)² + (Perpendicular)²
In ∆DEF,
- Hypotenuse, DF = 9 feet
- Perpendicular, DE = 4.5 feet
- Base, EF = ?
=> (9 feet)² = (EF)² + (4.5 feet)²
=> 81 feet² = (EF)² + 20.25 feet²
=> 81 feet² - 20.25 feet² = (EF)²
=> 60.75 feet² = (EF)²
=> EF = √60.75 feet = 7.79423
Hence, Side EF = 7.79423 feet or almost 7.80 feet.