The surface area of a right cone is 55π cm squared. Find the radius if the slant height is 6cm.

  1. 👍 0
  2. 👎 0
  3. 👁 149
  1. S.A. = πr(r + 6)

    55π = πr² + 6πr

    55 = r² + 6r

    r² + 6r - 55 = 0

    (r + 11)(r - 5) = 0

    r = 5 cm

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. Algrebra

    I need to find the approximate surface area of a cone with the R=5 and L=6. I thought I figured it out by 3.14(5)(6) which will give me 94.2 I then would take 94.2 +3.14(5)squared and I came up with 172.7, but my answer should be

    asked by Samantha on April 9, 2012
  2. Math

    A cone is formed from a sector of a circular of radius 9cm which sustained an angel 120 find (a) the radius of the cone formed (b) the curved surface area of the cone (c) the total surface (d) volume

    asked by Olawale olaniyi on February 8, 2017
  3. Math

    Completely bemused, do not know how to get the answer. a)8π b)7√2 c)27√π d)7√×7√×1 13- Determine the exact total surface area of a sphere with radius 2√2 metres. a) An inverted cone with side length 4 metres is

    asked by Ricky on February 25, 2016
  4. Algebra 1--How Am I Supposed to Solve This?!

    Suppose a cone and a cylinder have the same radius and that the slant height l of the cone is the same as the height h of the cylinder. Find the ratio of the cone's surface area to the cylinder's surface area. Area of cone: S =

    asked by Victoria on May 27, 2014
  5. geometry

    The surface area of a cone is 38 in^2. The radius of a similar cone is triple the radiusof the orginal cone. What is the surface area of the new cone?

    asked by Piggy on May 5, 2012
  6. Math

    Find the lateral area of the cone. Use 3.14 fo pi and round result to the nearest whole unit. radius: 15cm Side unit: 28cm Please help!! A) 1,319 cm squared B) 2,639 cm squared C) 707 cm squared D) 2,026 cm squared is the answer

    asked by Help PLEASE on January 13, 2015
  7. Geometry

    The surface area of a cone is 55 pie cm squared. The radius is 5 cm. What is the slant height?

    asked by Angela on May 13, 2012
  8. Math

    What is the surface area and volume of a composite figure made up of a hemisphere and a cone in terms of pi? The radius is 10, and the slant height is 15. Are my answers right? Cone surface area: π(10)(15) = 150π Hemisphere

    asked by Anonymous on May 26, 2015
  9. math

    The formula for the lateral surface area of a cone is A=πr√(h^2+r^2). (A)Solve for r and simplify the result, if possible. (B) If the lateral surface area of a cone is 10 square feet and the height is 16 inches, what is the

    asked by Andrea on April 24, 2018
  10. Mathematics

    solid is in the form of a cone mounted on himispher in such away that the Venter of the base of the cone fast coincide with the center of the base of the hemisphere.the radius of hemisphere and height of cone are r each ,radius of

    asked by Okram gojen on March 3, 2019

More Similar Questions