The given area of the shape of 57.8·π cm², and length of the slant sides
being a factor of the radius, gives the length of the radius as <u>3.4 cm</u>.
<h3>How can the length of the radius be calculated?</h3>
Given;
Radius of the two cones are equal.
Slant height of one cone = 2 × Radius
Slant height of the other cone = 3 × Radius
Surface area of the shape = 57.8·π cm²
The curved surface area of a cone = π·r·l
Required:
The radius of the cone.
Solution;
Surface areas of the cones are therefore;
π·r × 2·r, and π·r × 3·r
The total surface area is therefore;
π·r × 2·r + π·r × 3·r = 57.8·π
5·r²·π = 57.8·π
Which gives;
r² = 57.8 ÷ 5 = 11.56
r = √(11.56) = 3.4
- The radius of the cones, r =<u> 3.4 cm</u>
Learn more about finding the surface area of 3-D shapes here:
brainly.com/question/15635229
The amount of money in the account if compounded quarterly at 6% after 9 years is $22,217
<h3>Compound interest</h3>
- Principal, P = $13,000
- Time, t = 9 years
- Interest rate, r = 6% = 0.06
- Number of periods, n = 4
A = P(1 + r/n)^nt
= 13,000(1 + 0.06/4)^4×9
= 13,000(1 + 0.015)^36
= 13,000(1.015)^36
= 13000(1.709)
= $22,217
Learn more about compound interest:
brainly.com/question/24924853
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Answer:
Step-by-step explanation:
25% of classrooms is 3, find 100%
Since 100% is 4 times 25%, the corresponding number will also be 4 times greater:
Using a^2 + b^2 = c^2 it means that
42^2 + 56^2 = c^2
therefore c^2= 4900
so c=70mm
