Question

Magda saw a triangular sign with a base of 4 feet and a height of 2.8 feet. She reasoned that if she first divided each dimension by 2 before multiplying them together, she would get the right area. Is she correct? Explain.

Answer 1

Answer: She is not correct, because she must multiply the base and the height of the triangle and then divide by 2.

Step-by-step explanation:

1. The formula for calculate the area of a triangle is shown below:

$A=\frac{b*h}{2}$

Where $b$ is the base and $h$ is the height.

2. Then, if she applied the method she reasoned, she'd obtain the following area:

$b=\frac{4ft}{2}=2ft\\h=\frac{2.8ft}{2}=1.4ft\\A=2ft*1.4ft\\A=2.8ft^{2}$

 3. But actually, Magda should multiply the base and the height of the triangle and then divide by 2. Then, the correct area is:

 $A=\frac{4ft*2.8ft}{2}=5.6ft^{2}$

Answer 2

Answer:

No, Magda is incorrect. The actual area is 0.5(4)(2.8) = 5.6 ft2. With Magda's method, the area would be (2)(1.4) = 2.8 ft2.

Step-by-step explanation: