Grade 8 Perimeter & Area Quiz 1 draws its questions at random from 24 questions across these topics:
A few of the question types, with full solutions, so you know what to expect.
Perimeter. A square has sides of 17,5 cm. Calculate its perimeter.
Answer: 70 cm
Perimeter of a square: \( P = 4s \).
\( P = 4 \times 17{,}5 \)
Perimeter. An equilateral triangle has all three sides equal to 32 cm. Calculate its perimeter.
Answer: 96 cm
All three sides are equal (equilateral), so \( P = s+s+s = 3s \).
\( P = 32 + 32 + 32 \)
Perimeter. A rectangle has a length of 40 cm and a breadth of 25 cm. Calculate its perimeter.
Answer: 130 cm
Perimeter of a rectangle: \( P = 2(l+b) \).
\( P = 2(40+25) = 2(65) \)
Perimeter. This house shape is a rectangle with a triangular roof. All measurements are in cm and only outside edges count. Calculate the perimeter.
Answer: 48 cm
The 13 cm line where the roof meets the rectangle is inside the shape — it is not part of the perimeter.
Walk the outside edges: bottom (13) + left side (8,5) + left roof slant (9) + right roof slant (9) + right side (8,5).
\( P = 13 + 8{,}5 + 9 + 9 + 8{,}5 \)
Perimeter. This house shape has a rectangle 9 cm wide with sides of 15 cm, topped by an isosceles triangle roof with a slant of 5 cm on the labelled side. Calculate the perimeter.
Answer: 49 cm
The roof is isosceles, so both slants equal 5 cm. The rectangle's top edge (9 cm) is internal.
\( P = 9 + 15 + 5 + 5 + 15 \)