Answer:
l = 11 meters
Explanation:
Surface area = s² + 2s*l
Where "l" is the slant height
Given: Surface area = 279 ; side length s = 9
Now plug in these values in the above formula, we get
279 = 9^2 + 2*9*l
279 = 81 + 18*l
18l = 279 - 81
18l = 198
Dividing both sides by 18, we get
l = 198/18
l = 11 meters
Therefore, slant height of the square pyramid = 11 meters
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