JAMB - Mathematics (2010 - No. 39)
A cylindrical pipe 50m long with radius 7m has one end open. What is the total surface area of the pipe?
749\(\pi\)m2
700\(\pi\)m2
350\(\pi\)m2
98\(\pi\)m2
คำอธิบาย
Total surface area of the cylindrical pipe = area of circular base + curved surface area
= \(\pi\)r\(^2\) + 2\(\pi\)rh
= \(\pi\) x 7\(^2\) + 2\(\pi\) x 7 x 50
= 49\(\pi\) + 700\(\pi\)
= 749\(\pi\)m\(^2\)