Question

One quart of water-resistant paint covers 75 square feet. A swimming pool is in the shape of a rectangular prism with a length of 20 feet, a width of 10 feet, and a height of 5 feet. How many quarts should you buy to paint the swimming pool with two coats of paint?

Answer 1

Step-by-step explanation:

Prove that sin 20*sin40+sin60*sin80=3/16.

Answer:

Consider LHS

sin 20 × sin 40 × sin60 × sin80

Sin Values

sin 0° = √(0/4) = 0

sin 30° = √(1/4) = ½

sin 45° = √(2/4) = 1/√2

sin 60° = √3/4 = √3/2

sin 90° = √(4/4) = 1

LHS = sin60 [sin20 × sin40 × sin80]

LHS = √3/2[sin20 × sin(60 – 20) × sin(60 + 20)]

LHS = √3/2[sin 3(20)/4]

LHS = √3/2[sin 60/4]

LHS = √3/2[√3/2 × 4]

LHS = √3/2 × √3/8

LHS = 3/16

∴ LHS = RHS

Answer 2

Answer:

Step-by-step explanation:

First find the surface area of the pool, minus the top

F: 100

Ba: 100

Bot: 200

s1: 50

s2: 50

Then add

100+100+200+50+50=500

Then divide 75 into 500

500/75=7 (rounded)

Add 7+7

7+7=14

That should be your answer, it was right for me so if you still got it wrong maybe try using the decimal.