It say to find the area of the irregular shape and it's a semi circle with the diameter of 5 and a square measure 8 and I got the area of the rectantagle which is 40 and now I got to find the area of the semi circle but it say the radius for the formula and I can't find get the rest but I need to explain my answer. A. 90.2cm squared B.241cm squared C.65.1cm squared D 72.3cm squared PLZ HELP!
I ment I found the area of the rectangle I just need the semi circle and then add it up to find the amswe
A square of measure 8 does not have an area of 40.
A 5x8 rectangle has an area of 40.
You have a formula for the area of a circle, using its radius. Since the diameter is twice the radius,
πr^2 = π(d/2)^2 = πd^2/4
A circle of diameter d has area πd^2/4
you have a semicircle, so its area is πd^2/8 = 25π/8 = 9.82
40+25π/8 = 49.82
Hmmm. There must be something missing, since none of the answers comes even close.
Hmm -- maybe you do have a square of side 8.
64+25π/8 = 73.82
That looks close to D with a typo.
To find the area of the irregular shape, you need to calculate the area of both the rectangle and the semi-circle separately, and then add them together.
Let's start with the rectangle: The formula to find the area of a rectangle is length multiplied by width. You mentioned that the rectangle measures 8 units (assuming it's in centimeters), so the area of the rectangle is 8 multiplied by its corresponding width (which isn't provided). If the width is also 8, then the area would indeed be 64 square centimeters, not 40 as you mentioned.
Moving on to the semi-circle: The formula to find the area of a semi-circle is (π * r^2) / 2, where "r" represents the radius of the semi-circle. However, you mentioned that you only have the diameter of the semi-circle, which is 5 units.
To find the radius from the diameter, divide the diameter by 2. So in this case, the radius of the semi-circle would be 5 / 2 = 2.5 units.
Now, using the radius (r = 2.5), you can calculate the area of the semi-circle using the formula. Plugging in the values, the area of the semi-circle would be (π * 2.5^2) / 2 = π * 6.25 / 2 = 3.125π square units.
Finally, add the area of the rectangle (64 square centimeters) to the area of the semi-circle (3.125π square centimeters) to get the total area of the irregular shape.
Since the value of π is not provided, it is common to approximate it to 3.14 for calculations. By substituting this value and performing the addition, the total area of the irregular shape is approximately 64 + 3.125 * 3.14 ≈ 64 + 9.8175 ≈ 73.8175 square centimeters.
So, the closest option to the calculated answer would be D. 72.3cm squared (rounded to one decimal place).