Find the area of the regular decagon if the apothem is 5 inches and a side is 3.2 inches. round to the nearest whole number

When you are given the side length and apothem of a regular polygon and asked for area, you are expected to use the formula

... A = (1/2)Pa

where P is the perimeter of the polygon, "a" is the apothem, and A is the area.

The only additional information you need is that a decagon has 10 sides, so its perimeter is 10×3.2 inches = 32 inches.

The area is ...

... A = (1/2)(32 in)(5 in)

... A = 80 in²

Sometimes the dimensions of a problem like this don't quite add up. The geometry of a regular polygon means that the apothem can be found from the side length and vice versa. In this case, the side length of 3.2 inches means the apothem is about 4.92 inches; or the apothem of 5 inches means the side length is about 3.25 inches. Either way, the area is slightly different from that computed using the given numbers.

This is why I say you're expected to use the above formula. (You're not expected to think about it too much.)

25.2

step-by-step explanation:

2+4x6-8/10= 25.2

2 & 7

step-by-step explanation:

he climbs 300 ft/hr at a constant rate. the peak is at 1,500 ft.

when going up, he reaches 600 ft in 2 hours. remember, that he is going in a constant rate. divide 600 with 300:

600/300 = 2

assuming that he takes the same route back (meaning that it's a 1500 ft route back, you can solve.

note also that you are solving when he gets back to 600 ft after he reaches the peak.

first, find the amount of hours it takes to get up the peak. divide the total amount (1500), with the ft/her (300) to get the amount of hours (x):

1500/300 = x

x = 5

it takes jamie 5 hours to get up. now, he is returning down, and reaches 600 (his current destination). remember that he climbs at a constant 300 ft/hr. divide 600 with 300:

600/300 = x

x = 2

now add the two numbers together.

x = 5 + 2 = 7

jamie takes 7 hours to go up the mountain and reach his current position when descending.

(total amount/constant rate) = (time).

remember that it is a constant rate, so in total, when he gets back down the mountain, it will take the same amount of time as when he goes up. the total amount for the round trip is: 5 + 5 = 10.

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