The perimeter of the isosceles δabc with the base bc is equal to 40 cm. perimeter of the equilateral △bcd is 45 cm. find ab and bc.

The side lengths of an equilateral triangle are all the same, so each of the 3 sides is 1/3 of the total perimeter of the triangle. Here, that means ...

... BC = (1/3)×(45 cm) = 15 cm

The side lengths of an isosceles triangle are the same. Added to the base length, they give the perimeter.

... AB + AB + BC = 40 cm

... 2×AB + 15 cm = 40 cm . . . substitute the value of BC

... 2×AB = 25 cm . . . . . . . . . . subtract 15 cm

... AB = (25 cm)/2 = 12.5 cm

first option

a function is a relation in which an input is paired with exactly one output.

so, let's find the right answer.

in our first option, our inputs are january, february, and march. the outputs are 30, 28, and 25. each input has it's own output. this is correct!

our second option we know is incorrect, because ms. valverade has two outputs, dogs and cats. this is not a function.

our third option is incorrect as well. the yellow square has two ouputs, the square and the triangle.

lastly, in our fourth option, we see the number 7 two times with a different output. therefore, this is not a function.

remember: each input must be paired with only one output!

ans789

step-by-step explanation: