Question

The trapezoid is enlarged by a scale factor of 3, what is the area of the scaled copy?

Answer 1

360 cm²

Explanation:

The area (A) of the trapezoid is calculated as

A =
`(1)/(2)` h (b₁ + b₂ )

where h is the perpendicular height and b₁, b₂ are the parallel bases

Here h = 5 , b₁ = 10, b₂ = 6 , then

A =
`(1)/(2)` × 5 × (10 + 6) = 2.5 × 16 = 40 cm²

Enlarging by a scale factor of 3 means the area is increased by a factor

3² = 9

area of scaled copy = 9 × 40 cm² = 360 cm²

Answer 2

Explanation:

After enlargement,

Parallel sides are: 6*3 = 18 cm & 10*3 = 30cm

Altitude = 5 *3 = 15 cm

Area =[ (sum of the length of parallel sides)*height] ÷2

`= ((18+30)*15)/(2)\\= (48*15)/(2)\\\\= 24 *15\\\\= 360`