B
Hope this helps
Good luck
The answer to your question should be: ↓
F(3)= 2(3)^2-5(3)+9
=2(9)-15+9
=18-15+9
=3+9
=12
f(3)=12 or B
X=60° (equilateral triangle)
y=120°
Working: (360°-120°)/2
The midpoint lines are half the opposite side length.
Line DE is given as 7 , So Line F = 7 x 2 = 14
Line EF is given as 12, so Line D = 12 x 2 = 24
Line DF is given as 16, so line E = 16 x 2 = 32
The perimeter is the sum of the 3 sides:
Perimeter = 14 + 24 + 32 = 70