Explanation:
Volume of rectangular prism: Length * Width * Height
Solve:
<u></u>
<u>1)</u>
Volume: 9 * 9 * 9 = 9³ = 729 cm³
<u>2)</u>
Volume: 7 * 3 * 2 = 42 m³
<u>3)</u>
Volume: 7 * 7 * 7 = 7³ = 343 cm³
Answer:
-3.8 - (7.2-10 3/8)
-3.8+(-7.2+10 3/8) this is the error, it's positive 10 3/8, not negative, then you should solve what's in the parentheses first
I simplified 10 3/8 into 83/8 and then 10.375
-3.8+(-7.2 + 10.375)
-3.8+ 3.175 = -0.625
Question 1:We have a 45-45-90 right triangle with the hypotenuse being the length from one corner to the opposite corner.
Multiply 30 ft with the square root of 2 and use a calculator to help give you numerical value to get your answer.

Your answer is the second choice.
Question 2:The equilateral triangle can be divided into 2 30-60-90 triangles with the longer leg being the altitude. To get half of the side length of the right triangle, divide the altitude by the square root of 3.

The full side length is double of that, which is

.
Multiply that by 3 to get the full perimeter.

Your answer is the third choice. Hope this helps! :)