Question

Eth enlarged the triangle below by a scale of 5.

A triangle with a base of 4 centimeters and height of 3.5 centimeters.



She found the area of the enlarged triangle. Her work is shown below.


One-half (4) (3.5) (5) = 35 centimeters squared


What was Beth’s error?

She should have divided One-half (4) (3.5) by 5.

She should have divided One-half (4) (3.5) by 5 squared.

She should have multiplied (4) (3.5) by 5.

She should have multiplied One-half (4) (3.5) by 5 squared.

Answer 1

D

Explanation:

I got it right on my quiz on Edgen 2020

Answer 2

She should have multiplied one half (4)(3.5) by 5 squared.

Explanation:

We are given that

Base of triangle=b=4 cm

Height of triangle=h=3.5 cm

Area of triangle=
`(1)/(2)bh=(1)/(2)(4)(3.5) cm^2`

After enlarged

Scale factor=5

New base of enlarged triangle=b'=4(5) cm

Height of enlarged triangle=h'=3.5(5) cm

Area of enlarged triangle=
`(1)/(2)4(5)(3.5* 5)=(1)/(2)(4)(3.5)(5^2) cm^2`

But Beth wrote

Area of enlarged triangle=
`(1)/(2)(4)(3.5)(5)=35 cm^2`

She should have multiplied one half (4)(3.5) by 5 squared.