The first thing you need to do is find the radius of the semicircle. To do that you look to see that the width of the rectangle is the same as the radius. Once you have the Area of a Semicircle calculated multiply it by 3. then, we know that the other length of the rectangle is 3 diameters of a semicircle this means that you multiply the radius of 7 by 6 which gives you 42. You take the area of the rectangle (294) and subtract the area of the 3 semicircles(230.79) Which gives you the answer of 63.21cm^2
Answer:
The amount invested at 3% is 300 &
The amount invested at 2% is 100.
Step-by-step explanation:
Total yearly interest for the two accounts is: $11
Let x be the amount invested at 3%
& y be the amount invested at 2%
From the question we can get 2 equations as;
x = 3y --------------------------Equation 1
0.03x + 0.02y = 11 ----------Equation 2
Substitute for x in Equation 2 we get;
0.03 (3y) + 0.02y = 11
0.09y + 0.02y = 11
0.11y = 11
Divide the above equation by 0.11, we get;
y = 
y = 100
Let us substitute the value of y in Equation 1 we get;
x = 3(100)
x = 300
Now to check our answer let us put in the simple interest formula. If we get the sum of the two interests equal to 11 then our answers are correct:
0.03 x 300 + 0.02 x 100
= 9 + 2
= 11
Hence the amount invested at 3% is 300 and the amount invested at 2% is 100.