First, convert all of the cm measurements to m measurements (so they are all the same unit measurement)
2000 cm = 20 m 800 cm = 8m
<u>Total Perimeter </u>(Note that circumference of a semi-circle is 2 π r/2 = π r)
Add up the lengths of all of the outside edges. I am going to start on the top and move counter-clockwise:
40 + π (10) + 8 + 25 + 8 + (40 - 25 - 10) + 8 + 10 + 8 + π(10)
= 40 + 10π + 41 + (5) + 26 + 10π
= 112 + 20π
= 112 + 62.8
= 174.8
Answer: 174.8 m
<u>Total Area</u>
Split the picture into 5 sections (2 semi-circles, top rectangle, bottom left rectangle, and bottom right rectangle). Find the area for each of those sections and then add their areas together to find the total area.
2 semi-circles is 1 Circle: A = π · r² ⇒ A = π(20/2)² = π(10)² = 100π ≈ 314
top rectangle: A = L x w ⇒ A = 40 x 20 = 800
bottom left rectangle: A = L x w ⇒ A = 25 x 8 = 200
bottom right rectangle: A = L x w ⇒ A = 10 x 8 = 80
Total = 314 + 800 + 200 + 80 = 1394
Answer: 1394 m²
we can use formula

where
fL is listener frequency
fs is siren frequency
va is the speed of sound in air
vs is police car speed
so, we have



now, we can change it into m/s


now, we can plug it

..............Answer
<u>Answer</u>
D
<u>Explanation</u>
9⁽¹/²⁾² = (9⁽¹/²⁾)²
= 9¹/² × 9¹/² (Since the base are the same, we can add the power.)
= 9⁽¹/² ⁺¹/²⁾
= 9 ¹
= 9
The correct simplification is D.
Notice that both A and B are multiplied by (1/2).
Thus, the given expression can be re-written as [(1/2)(A+B)]^2.
Square the (1/2) and the (A+B) separately, and then multiply together the resulting squares:
(1/4)(A^2 + 2AB + B^2)