Mensuration Practice Test 1

Area of the central park = L × b
= 40 × 30 = 1,200 ${\mathit{m}}^2$
Area of cross roads (let us suppose that width = x)

Area of PQRS + Area of TUVW − Area of LMNO
40 × x + 30 + x − ${\mathit{x}}^2$
40x + 30x − ${\mathit{x}}^2$
70x − ${\mathit{x}}^2$
According to the statement, area of cross roadsis half the area of the rectangle.
70x - ${\mathit{x}}^2$ = $\frac{1200}{2}$
70x − ${\mathit{x}}^2$ = 600
$-{\mathit{x}}^2$ + 70x − 600 = 0
${\mathit{x}}^2$ + 70x + 600 = 0
${\mathit{x}}^2$ − 60x −10x + 600 = 0
x(x − 60)−10(x − 60) = 0
x = 60, 10
x = 60
Impossible
Width = x = 10 meters