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
Answer:B
Step-by-step explanation:
50
Step-by-step explanation:
Since AE is the bisector of angle BAC,so angle BAE and Angle CAE is equal. Here Angle CAE and Angle EAC is same.
therefore,
m(Angle BAE)=m(Angle EAC)

or, 2x=40
or, x=20
Hence,
m(Angle EAC)=

=

Answer: 102
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We'll use the formula
A = h*(b1+b2)/2
where
A = area of trapezoid
h = height
b1 & b2 are the parallel bases
In this case,
b1 = 6+7 = 13
b2 = 21
h = 6
Making the area to be
A = h*(b1+b2)/2
A = 6*(13+21)/2
A = 6*(34)/2
A = 204/2
A = 102
Side Note: We don't use the slanted side of 10 cm at all