A certain square pyramid has a volume of 100 cm^3. A similar but smaller pyramid has a surface area equal to one fifth of the larger. What is the volume of the smaller pyramid?
1 Answer
Feb 13, 2018
Explanation:
"consider 2 similar figures then"
"linear ratios "=a:b
"area ratios "=a^2:b^2
"volume ratios "=a^3:b^3
"here "a^2:b^2=1:5
rArra:b=sqrt1:sqrt5=1:sqrt5
rArra^3:b^3=1^3:(sqrt5)^3=1:5sqrt5
rArr"volume of smaller pyramid "=100/(5sqrt5)
rArr"volume "=20/sqrt5xxsqrt5/sqrt5=4sqrt5" cubic cm"