Which is a perfect square? 72 81 90 99

81 is perfect square.

Step-by-step explanation:

Given numbers  72 81 90 99 .

We have to choose the number out of given options that are perfect squares.

PERFECT SQUARES  are those numbers that be written as product of two equal numbers. Also perfect squares are those numbers that can be written as square of a number.

Thus, for given numbers

1) 72 = 8 × 9

2) 81= 9 × 9

3) 90=   9 × 10

4) 99 =  9 × 11

Thus, out of given option only 81 is written as product of two equal numbers.Thus 81 is perfect square.

the sum of the lengths of any two sides of a triangle is greater than the length of the third side. if you take the three sides of a triangle and add them in pairs, the sum is greater than (not equal to) the third side. if that is not true, then it is not possible to construct a triangle with the given side lengths.

step-by-step explanation:

she gotta workk that a 2

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