Associative property
(a+b)+c=a+(b+c)
Answer:
10/7 or 1 3/7. I hope this helps,
Step-by-step explanation:
Answer:
5. 6.1 units
6. 29.4 units
7. 12.8 units
8. 29.1 units
Step-by-step explanation:
5. We have the opposite and adjacent sides here for angle 21 degrees. So we need to use tangent, which is opposite / adjacent:

≈ 6.1 units
6. We have the opposite and hypotenuse sides here for angle 33 degrees. So we need to use sine, which is opposite / hypotenuse:

≈ 29.4 units
7. We have the opposite and adjacent sides here for angle 37 degrees. So we need to use tangent, which is opposite / adjacent:

≈ 12.8 units
8. We have the opposite and hypotenuse sides here for angle 31 degrees. So we need to use sine, which is opposite / hypotenuse:

≈ 29.1 units
Hope this helps!
Answer:
18cm
Step-by-step explanation:
We have the length of the rectangle but we need to find the width which we'll call w. Area is a, l is length.
a = l * w
20 = 5 * w
divide both sides by 5 to cancel the multiplication by 5 on the right side
4 = w
The rectangle is going to have two sides that are the length of l, and two sides that are the the length of w. We're looking for the perimiter p.
p = 2l + 2w
p = (2 * 5) + (2 * 4)
p = 18