Jordana was shown this diagram of an isosceles trapezoid and its reduction. She was asked to find the perimeter of the reduced t
rapezoid. Her work is shown below. A trapezoid with side lengths 30 centimeters, 12 centimeters, and 36 centimeters. A trapezoid with side lengths A, 4 centimeters, B.
Figures not drawn to scale.
Jordana’s Work
Scale factor
StartFraction 4 over 12 EndFraction = one-third
Side A
30 times one-third = 10
Side B
30 times one-third = 10
Perimeter
10 + 10 + 4 + 4 = 28
Where, if any, did Jordana first make a mistake in her work?
Jordana made a mistake when finding the scale factor.
Jordana made a mistake when she calculated the length of side A.
Jordana made a mistake when she calculated the length of side B.
Jordana did not make any mistakes in her work.
After h hours A has 6000 - 2000h cells and B has 2000 - 1000h. Equating them as one form: 6000 - 2000h = 2000 - 1000h -2000h + 1000h = 2000 - 6000 -1000h = -4000 h = -4000/-1000 = 4 hours