A=1/2bh
b=8+h
A=384
384=1/2(bh)
times 2
768=bh
sub
768=b(8+b)
768=8b+b^2
minus 768 both sides
0=b^2+8b-768
factor
0=(b-24)(b+32)
set to zero
b-24=0
b=24
b+32=0
minus 32
b=-32
false, legnths cannot be negative
b=24
24=8+h
minus 8
16=h
base=24ft
altetude=16ft
His estimate is reasonable. But only if Michael is less than 2 years old.
answers
1) 70
2) 3,840
3) 24
4) 72
<u>Explanation</u>
Q1
The surface area of a cone is given by;
S.A = 2Πrl + Πr²
Where r is the radius of the base and l is the lateral height.
Πr² = area of the base = 20 in²
2Πrl = Area of the lateral surface
= 2.5 × 20
= 50
Area of the cone = 50 + 20
= 70 in²
Q2
The sides of the Pythagorean triangle with legs of 12 and 16.
The 3rd side will be;
c = √(12² + 16²)
= √400 = 20
Volume = 12 × 16 × 20
= 3,840
Q3
The volume of a cone is given by;
volume = 1/3 Π r² h
This shows that the volume of a cone is a third the volume of the cylinder.
∴ Volume of the cylinder = 12 × 3
= 24 ft³
Q4
The volume of any regular figure is;
Volume = base area × height
When the dimensions area usually 3. Let these dimensions be x, y and z.
∴ volume = x × y × z = 9
Doubling the dimensions;
Volume = 2x × 2y × 2z = 2 × 2 × 2 × 9
= 8 × xyz = 8 × 9
= 72 ft²
a xuz if u work it out ull get a
A) x/6=9
Subtract 6 from both sides, x=3
B) x/-4=-3
Add 4 to both sides, x=1
C) x/-5=7
Add 5 to both sides, x=12
