Answer:
The area of the triangle is 
Step-by-step explanation:
Given:
Coordinates D (0, 0), E (1, 1)
Angle ∠DEF = 60°
△DEF is a Right triangle
To Find:
The area of the triangle
Solution:
The area of the triangle is = 
Here the base is Distance between D and E
calculation the distance using the distance formula, we get
DE = 
DE =
DE = 
DE = 
Base = 
Height is DF
DF =
DF = 
DF = 
Now, the area of the triangle is
= 
=
=
=
Sharon's age= 2x
Brian's age= x
(2x-5)+(x-5)= 25
3x-10=25
3x=15
x=5
Brian is 5 years old and Sharon is 10