The Red Sun Plaza originally had a rectangular flower bed, 40 meters long. Later, when it was expanded, the length was increased by 20 meters, resulting in an increase of 400 square meters in area. How many square meters does the flower bed now cover?

The Red Sun Plaza originally had a rectangular flower bed, 40 meters long. Later, when it was expanded, the length was increased by 20 meters, resulting in an increase of 400 square meters in area. How many square meters does the flower bed now cover?

(40 + 20) × (400 ／ 20) = 60 × 20 = 1200 square meters. A: the garden now covers an area of 1200 square meters

There is a rectangular fish pond, 20 meters long. Later, the length of the fish pond increased by 5 meters and the area increased by 75 square meters. How many square meters does the original fish pond cover?

Width 75 △ 5 = 15m
It covers an area of (20 + 5) x15 = 25x15 = 375 square meters
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The campus of Lixin primary school is a rectangle with a length of 80 meters and a width of 60 meters. After the width was built, the length and width have increased by 20 meters. How many square meters is the current campus area?

（80+20）X（60+20）
=100*80
=8000 square meters
I don't know about blockhouses