Answer:
B,C,E
Step-by-step explantion
plz mark brainliest if correct
We can see that revolving the region formed by intersecting 3 lines, we will get 2 cones that are connected their bases.
Volume of the cone V=1/3 *πr²*h
1) small cone has r=5, and h=5
Volume small cone V1= 1/3 *π*5²*5 = 5³/3 *π
2) large cone has r=5, and h=21-6=15, h=15
Volume large cone V2= 1/3 *π*5²*15 = 5³*π
3) whole volume
5³/3 *π + 5³*π=5³π(1/3+1)=((5³*4)/3)π=(500/3)π≈166.7π≈523.6
Area
we see 2 right triangles,
Area of the triangle=1/2*b*h, where b -base, h -height
1) small one, b=5, h=5
A1=(1/2)*5*5=25/2
2)large one, b=5, h=15
A2=(1/2)*5*15=75/2
3)
whole area=A1+A2=25/2+75/2=100/2=
50
Answer:
1. 5/3 cm
2. 10 in
Step-by-step explanation:
1. The length of a rectangle is 4 cm more than 3 times its width.
Let the length be L and the width B
Then,
L = 4 + 3B
If the area of the rectangle is 15 cm2
Area = LB = 15
B(4 +3B) = 15
3B² + 4B - 15 = 0
3B² - 5B + 9B - 15 = 0
B(3B - 5) + 3(3B - 5) = 0
(3B - 5)(B + 3) = 0
3B - 5 = or B + 3 = 0
B = 5/3 or -3
since B cannot be negative, B = 5/3 cm
2. The ratio of length to width in a rectangle is 2 ∶ 3.
Let the length be L and the width B
Then,
L/B = 2/3
2B = 3L, B = (3/2)L
when the area is 150 in2.
Area = LB = 150
(3/2)L² = 150
L² = 150×2÷3
L² = 100
L = √100
L = ±10
since the length cannot be negative, L = 10 in