Answer:
![Both \: the \: moon \: and \: earth \: are \: in \: \\ the \: shape \: of \: spheres. \\ Surface\: area \: of \: a \: sphere \: of \: radius \: 'r' \\](https://tex.z-dn.net/?f=Both%20%5C%3A%20%20the%20%5C%3A%20%20moon%20%20%5C%3A%20and%20%20%5C%3A%20earth%20%20%5C%3A%20are%20%20%5C%3A%20in%20%5C%3A%20%20%5C%5C%20%20the%20%20%5C%3A%20shape%20%5C%3A%20%20of%20%20%5C%3A%20spheres.%20%5C%5C%20Surface%5C%3A%20area%20%20%5C%3A%20of%20%5C%3A%20%20a%20%5C%3A%20sphere%20%20%5C%3A%20of%20%20%5C%3A%20radius%20%5C%3A%20%20%27r%27%20%5C%5C%20)
Let d1 be the diameter of the moon and d2 and be the diameter of the earth.Let r1 be the radius of the moon and r2 be the radius of the earth.
![given \: d1 = \frac{1}{4}d2 \\ = > 2r1 = \frac{1}{4} ×2r2 \\ =>r1 = \frac{1}{4}×r2 \\ Now, \: ratio \: of \: \: their \: surface \: areas \: is: \\ = s1: s2 \\ = r {1}^{2}: r {2}^{2} \\ = {1}^{2 } : {4}^{2 } \\ =1:16](https://tex.z-dn.net/?f=given%20%5C%3A%20d1%20%3D%20%20%5Cfrac%7B1%7D%7B4%7Dd2%20%5C%5C%20%3D%20%3E%202r1%20%3D%20%20%5Cfrac%7B1%7D%7B4%7D%20%C3%972r2%20%20%5C%5C%20%20%3D%3Er1%20%3D%20%20%5Cfrac%7B1%7D%7B4%7D%C3%97r2%20%5C%5C%20Now%2C%20%20%5C%3A%20ratio%20%5C%3A%20%20of%20%5C%3A%20%20%5C%3A%20%20their%20%20%5C%3A%20surface%20%5C%3A%20%20areas%20%5C%3A%20%20is%3A%20%20%5C%5C%20%3D%20%20s1%3A%20s2%20%5C%5C%20%20%3D%20r%20%7B1%7D%5E%7B2%7D%3A%20r%20%7B2%7D%5E%7B2%7D%20%5C%5C%20%3D%20%7B1%7D%5E%7B2%20%7D%20%3A%20%7B4%7D%5E%7B2%20%7D%20%5C%5C%20%3D1%3A16)
<h2> hope it helps you</h2>
Answer:
Perimeter of △BDC=Sum of all the sides=BD+DC+CB=15+15+15=45
Step-by-step explanation:
Given ΔABC is an isosceles triangle, thus, AB=BC=x and AC=12,
perimeter of △ABC is=42
⇒x+x+12=42
⇒2x=30
⇒x=15
Thus, AB=BC=15
Now, △BDC is an equilateral triangle therefore BD=DC=BC=x
Since, x=15, therefore BD=DC=BC=15
Now, Perimeter of △BDC=Sum of all the sides=BD+DC+CB=15+15+15=45
Answer: 9/12, 2/12
Step-by-step explanation:
Start by writing multiples of 6 and 4
4: 4, 8, 12
6: 6, 12, 18
Did you see the multiple that both numbers have? Yup, it's 12. So that has to be your denominator for both fractions. This is because you have to have the <u>LEAST</u> COMMON Denominator (LCD). So both numbers have 12 in common as one of their multiples and, it's the least common one because there are no numbers that come before it that are common for both numbers. Now, you just have to change the denominators of both fractions into 12. To do that to 3/4, just multiply the top and bottom by 3 to get 9/12. To do that to 1/6, just multiply the top and bottom by 2 to get 2/12. Hope this helps!
NOTE: REMEBER THAT WHATEVER YOU DO TO THE TOP OF A FRACTION, YOU HAVE TO DO IT TO THE BOTTOM TOO (AND VICE VERSA)
Answer:
15 cm
Step-by-step explanation:
Similar triangles are triangles which have the same shape but not the same size. This means their angle measures are equal but their side lengths are not instead they are proportional. To solve, we will set up a proportion and solve.
A proportion is two equal ratios set equal to each other. We form the ratios by finding corresponding sides (sides which match to each other on both triangles by their position). Out ratios will be one side of the small triangle over the corresponding side on the big triangle as shown below:
.
To solve the proportion, we'll cross multiply by multiplying numerator with denominator across the equal sign.