Marlo's Square root post

Question:

1.) Explain how to estimate the square of number 28 to one decimal place without using a calculator. (Page 98)

Answer:

First you have to find the two closest square numbers before and after 28 then you have to place them in a number line just like this:

Now you have to guess where the number would be the closest to and then you need to put the decimal number that you think it is underneath, I picked 5.3 cause I know that 28 is fairly close to 25.

Question:

11.) The square has an area of 20cm2 Use perfect square to estimate the side length to one decimal place.

Answer:

Question:

17.)Carmel wants to mount an 18 cm x 18 cm square picture on a square board that is four times the area of the picture.

a.)What is the area of the picture?

b.)What is the area of the board?

c.)What are the dimensions of the board?

Answers:

A.) In order to find the area of the picture first you have to remember that side x side would be the the area, so the area for the picture here would be 324.

B.) For the second part the answer would be 1,296cm2 because in the statement it states that the board is 4 times the area of the picture so it goes like this 324 x 4 = 1,296.

C.) In order to get the dimension of the board you just have to find the square root of 1296cm2 which would be 36. 36 x 36= 1,296

Oh and heres a video that helped me with my post:

*Edit* February 5, 2012

1. Answer in a short paragraph and with diagrams.

Basically the Pythagorean relationship is the relationship between two side lenghts of a
right triangle. It also says that both the areas of the legs are going to be the same value as the hypotenuse. You must also remember that the hypotenuse is always the largest number.

2.) Find the missing side lenghts.

The answer would be 13 cm because 12 would be A and 5 would be B so it goes like this:

A² + B² = C²

12² + 5² =C²

144cm + 25cm =169

√169= 13 cm

This is how I got it on my paper:

3.)Is this a right triangle? Prove it!!!

No it's not.