9514 1404 393
Answer:
260π in²
Explanation:
The slant height is the hypotenuse of a right triangle with legs 10 and 24. Using the Pythagorean theorem, we find it to be ...
l² = 10² +24² = 100 +576 = 676
l = √676 = 26
The given formula tells you the lateral area is ...
A = πrl = π(10 in)(26 in)
A = 260π in² . . . . . cone's lateral area
_____
Additional comment
The name of the constant relating diameter to circumference (π) is "pi". It is the 16th letter of the Greek alphabet. "Pie" is something else entirely.