Answer:
30 cm
Explanation:
So what we are given here is a case of similar figures.
When we are given similar figures, the ratio of the width of both figures should be similar to the ratio of the length of both figures.
I'll demonstrate it in the following problem.
We know one rectangle has a length of 18 cm and a width of 6cm.
The other rectangle has a width of 10 cm.
Let's take a ratio of the width of both rectangles.
We take the width of 6 cm for the first rectangle to the width of 10 cm for the second rectangle.
w1 = 6 cm
w2 = 10 cm
6 cm : 10 cm = 3 : 5
The ratio given is 3 : 5. Let's use these ratios to find lengths.
l1 = 18 cm
l2 = x cm
3 : 5 = 18 : x
To find x, we just solve this like an equation, where we let ratios be division signs.
3/5 = 18/x
Multiply both sides by 5x
3x = 90
Divide both sides by 3
x = 30 cm
The length of the missing side is 30 cm. We found the answer to the length by using the ratios obtained from the widths.