Question

8. You have been asked to repaint the lateral surface area of cone-shaped pylons used for soccer drills. If they have a radius of 5" and a height of 12", calculate the slant height and lateral surface area to be painted to the nearest square inch.??
​

Answer 1

Answer:

See answer below.

Step-by-step explanation:

LA = π rl

1st find l    

The radius is 5" and the height is 12"  l = ?

  h and the r is the two legs in the right triangle when drawn in a cone.

Use a²  + b² = c²     ⇔ h² + r² = l²

                                    12² + 5²  = l²

                                   144 + 25 = l²

                                     169 = l²

                                    $\sqrt{169} = l$

                                        13 = l

Formula for LA = π r l

                  LA = 3.14 × 5 ×13  or with a calculator   LA = π × 5 × 13

                   LA = 204.1  sq.in                                   LA  = 204.2035225 sq. in

I use 3.14 = for π  but you know what the teacher uses in class.