sin 90 is simply 1, pretty straightforward
Step-by-step explanation:
first of all, your teacher wrote nonsense in the answer options : an area is always given in squared units. never in cubed units (which would be volume).
the area is : 1/2 × perimeter × apothem
the perimeter is simply 12 × 5 = 60 meters.
apothem = (a/2)×cot(pi/12) = 5/2 × cot(pi/12) =
= 9.330127019... meters
so the area is
1/2 × 60 × 9.330127019... = 279.9038106... m²
therefore, the third answer option is correct (although it is m², and not m³).
by the way, you have question 3 wrong. I answered this with the correct apothem calculation in the explanation for question 4.
The independent variable of an equation is x, or something u can change. in linear equations, for example, it is y=3x+4. and x is the independent variable cause most of the time u will plug in or substitute a number for x.
Answer:
It means that above 0 degrees Celsius the water does not freeze, whereas 0 degrees are freezing teperatures of water.
Step-by-step explanation:
Water freezes at 0 degrees Celsius, but the freezing temperature can be lowered by adding salt to the water. A student discovered that adding half a cup of salt to a gallon of water lowers its freezing temperature by 7 degrees Celsius. What is the freezing temperature of the gallon of salt water?
0° - 7° = -7°
