Miriam is trying to find the volume of the water tank shown in the photograph on the right - Junior Cycle Mathematics - Question 13 - 2015

From the diagram, we can set up the equation for the angle of elevation to the top:

$x + h = 20 an(38^ ext{o})$

We already found that $x = 11.55$ m, thus:

$11.55 + h = 20 imes an(38^ ext{o})$

Calculating:

Cylinder

Diameter = 5 cm Radius = 2.6 cm (since radius is half of the diameter) Height = 2.2 cm

To find the actual radius in meters:

Actual ext{ radius } = rac{4.5}{2.2} imes 2.6 = 5.318... ext{ m}

To find the volume of the cylinder:

Volume = rac{ heta imes r^2 imes h = heta imes (5.318...)^2 imes 4.5 }

Calculating gives:

$Volume ext{ of water tank } = 400 ext{ m}^3 (nearest m³)$