The total area of the blades is the area of a triangle multiplied by 4.
We have then:

Where,
b: base of the blades
h: height of the blades
Substituting values we have:

Doing the calculation we have that the area of the blades is given by:

Answer:
The total area of the blades is:

Answer:
8
Step-by-step explanation:
18-12
12-X
X=12*12/18
X=8mm
Answer:40
Step-by-step explanation:+$)#)#
Answer:
x = 65°
Step-by-step explanation:
The interior angle of the triangle and 140° are adjacent and supplementary, thus
interior angle = 180° - 140° = 40°
The exterior angle of a triangle is equal to the sum of the 2 opposite interior angles.
105° is an exterior angle of the triangle, thus
x + 40° = 105° ( subtract 40° from both sides )
x = 65°