A certain right triangle with integer side lengths has perimeter $72$. What is its area?

216 square units

Explanation:

A common pythagorean triple you may be familiar with is the 3-4-5 right triangle. This has two legs of 3 and 4, and a hypotenuse of 5. The perimeter is 3+4+5 = 7+5 = 12. Note how this is a factor of 72.

If we multiply the perimeter (12) by 6, then 12*6 = 72. So we have scaled the triangle by a factor of 6. Each length is 6 times longer

the side length 3 becomes 3*6 = 18

the side length 4 becomes 4*6 = 24

the side length 5 becomes 5*6 = 30

The new perimeter is 18+24+30 = 42+30 = 72

The last step is to find the area. The two legs of this triangle are the base and height

area = 0.5*base*height

area = 0.5*18*24

area = 9*24

area = 216

Or you could find the area of the 3-4-5 right triangle to get

area = 0.5*base*height = 0.5*3*4 = 6

then multiply by 36 to get 6*36 = 216. The 36 is the square of the scale factor 6 we applied above. The new lengths are 6 times longer, so the new area is 6^2 = 36 times larger.

b: |12 – x| ≤ 0.25

step-by-step explanation:      

let x be the possible lengths in inches, of the ribbons jaime cut.

we have been given that jaime is cutting strips of ribbon for a project. he tries to cut each piece to be 12 inches long, but sometimes he cuts it too long or too short by as much as 0.25 inch.  

we can represent this information in an inequality as:

by the definition of absolute value function we will get,

upon combining our inequalities we will get,

therefore, the inequality   describes all the possible lengths (x), in inches, of the ribbons jaime cut.

step-by-step explanation: