Answer:
Step-by-step explanation:
Perimeter = 84 cm
2*(length + width) = 84
2* (2x - 8 + x - 2) = 84
2*(2x + x - 8 - 2) = 84 {bring like terms together}
2*(3x - 10) = 84 {add/ subtract like terms}
Divide both sides by 2
3x - 10 = 42
3x - 10 +10 = 42 + 10 {add 10 to both sides}
3x = 52
Divide by 3,
x= 17 1/3
Length = 2x - 8
Answer:
A) Area as function of H ,
F'(a) = 2 +H
B) Area of triangle with height 6ft = 30 ft²
Step-by-step explanation:
Given as for a triangle ,
Let the height of triangle = H ft
And base = 4 ft + H ft
Now area of triangle = × height × base
F (a) = × H × ( 4ft + H ft)
Or, F (a) = × ( 4H + H² )
Now, here Area is function of height ,
So , F'(a) = (4 + 2H)
Hence Area as function of H ,
F'(a) = 2 +H
Now For height = 6 ft
Area of triangle = × height × base
= × H × ( 4ft + H ft)
= × ( 4H + H² )
= × ( 24 + 36 )
= × ( 60 )
= 30 ft²
Hence Area of triangle with height 6ft = 30 ft² Answer