The radius of a circle is 4 centimeters. What is the area of a sector bounded by a 180° arc?
r=4 cm
180°
Give the exact answer in simplest form.

8π cm²

Step-by-step explanation:

1. Area of a sector (Degrees)=(Ф/360)*πr²

 Ф= theta

 r=radius

 180/360*π*4²

 1/2*16π

 8π cm²

2. Since the angle is 180°, that means the area is semicircle. The degrees of the whole circle is 360° and half is 180°.

The calculations are still the same.

Area of a semicircle=1/2(πr²)

  1/2 (π*4²)

  16/2 π

  8π cm²

d

step-by-step explanation:

hello and welcome!

so, when we see the words "proportional" along with a table, we need to know that we're looking numbers that divide by the same thing.

looking at this table, we simply have to do a trial and error, and divide to see which numbers have the same quotient. if you look at choice a & c, they both have equal quotients for three of the numbers, with one exception, so those can't be the answer. looking at b, there is no similarity, so that can't be it. then, we see d; if you divide all the numbers in the table, you'll see that they all divide by two, which is a proportional relationship, and our answer!

also, always remember that the x will always be the number that goes into y, and somewhere behind this table, is a formula. for this specific table, the formula would be:

since our x-value is being divided by two to get the y-value. and if they were to ask for more numbers in the series, this is the formula you would use to find them.

x + y = 90 5x – 10y = 90 90 – 10y = 5x 90 + 10y = 5x

step-by-step explanation:

last month maria hiked the 5-mile mountain trail a number of times and she hiked the 10-mile canal trail several times. let x represent the number of times she hiked the 5-mile trail, and let y represent the number of times she hiked the 10-mile trail. if she hiked a total of 90 miles, which equation can be used to find the number of times maria hiked each trail? x + y = 90 5x – 10y = 90 90 – 10y = 5x 90 + 10y = 5x