Area and perimeter：練習問題

A rectangle has a length of 15 cm and a width of 8 cm. Calculate its perimeter.

A rectangle measures \(10 \text{ cm}\) by \(6 \text{ cm}\). A semicircle with a diameter of \(6 \text{ cm}\) is removed from one of the shorter sides. Calculate the perimeter of the remaining shape. Leave your answer in terms of \(\pi\).

A rectangular piece of card measures \(20 \text{ cm}\) by \(15 \text{ cm}\). Four identical circles, each of radius \(3 \text{ cm}\), are cut out from the card. Calculate the remaining area of the card, correct to one decimal place.

The area of a square is 64 \(cm^2\). What is its perimeter?

In the diagram, the diagonals of a rhombus measure \(12 \text{ cm}\) and \(16 \text{ cm}\). Calculate the area of the rhombus.

A square has an area of \(64 \text{ cm}^2\). Calculate the perimeter of this square.
Give your answer in centimetres. <\/p>

A circle has an area of \(49\pi \text{ cm}^2\). Calculate its circumference, leaving your answer in terms of \(\pi\).

A circle of radius \(r\) is enclosed perfectly within a square such that the circle touches all four sides of the square. Calculate the area of the square that is outside<\/i> the circle, giving your answer in terms of \(r\) and \(\pi\).<\/p>

A rectangle has a length of \(15 \text{ cm}\) and a width of \(w \text{ cm}\). The perimeter of the rectangle is \(46 \text{ cm}\).
(a) Calculate the value of \(w\).
(b) Calculate the area of the rectangle.

A trapezium \(ABCD\) has parallel sides \(AB = 8 \text{ cm}\) and \(CD = 14 \text{ cm}\). The area of the trapezium is \(77 \text{ cm}^2\).
(a) Calculate the perpendicular distance, \(h\), between the parallel sides.
(b) If a second identical trapezium is joined to the first along the side \(CD\) to form a larger hexagon, state the total area of the new shape.