Question

Angle DEF is a right triangle. If FE = 12 and DE = 5, find DF.

60

34

7

13

Answer 1

Option D is correct.

side DF = 13 units

Explanation:

Using Pythagoras theorem:

`\text{Hypotenuse side}^2=\text{Opposite side}^2+\text{Adjacent side}^2` ....[1]

In a right angle triangle DEF:

FE = 12 units and DE = 5 units.

Using Pythagoras theorem on DEF we have;

Hypotenuse side = DF

Opposite side = DE and Adjacent side = FE

Substitute these in [1] we have;

`DF^2 = 5^2+12^2 = 25 +144 = 169`

⇒
`DF = √(169) = 13` units.

Therefore, the side DF = 13 units

Answer 2

c^2=a^2+b^2

c^2 = 12^2 + 5^2

C^2 = 144 +25

C^2 = 169

c=13

DF = 13