Your Progress - Chapter 90% complete
1Exercises6 questions
Q.1Find the area of a trapezium whose parallel sides are 8 cm and 12 cm and height is 5 cm.v
Solution
Area $=\dfrac12(a+b)h=\dfrac12(8+12)5=50$.
Answer:
$50\text{ cm}^2$.
Q.2Find the area of a rhombus whose diagonals are 16 cm and 12 cm.v
Solution
Area $=\dfrac12 d_1d_2=\dfrac12\times16\times12=96$.
Answer:
$96\text{ cm}^2$.
Q.3Find the area of a polygon by splitting it into triangles and rectangles.v
Solution
The chapter method is decomposition into rectangles, triangles or trapezia.
Answer:
Split the polygon into known shapes, find each area separately, and add them.
Q.4Find the curved surface area of a cylinder of radius 7 cm and height 10 cm.v
Solution
Curved surface area $=2\pi rh=2\times\dfrac{22}{7}\times7\times10=440$.
Answer:
$440\text{ cm}^2$ using $\pi=\dfrac{22}{7}$.
Q.5Find the volume of a cuboid of length 12 cm, breadth 8 cm and height 5 cm.v
Solution
Volume $=lbh=12\times8\times5=480$.
Answer:
$480\text{ cm}^3$.
Q.6Find the volume of a cylinder of radius 7 cm and height 10 cm.v
Solution
Volume $=\pi r^2h=\dfrac{22}{7}\times49\times10=1540$.
Answer:
$1540\text{ cm}^3$ using $\pi=\dfrac{22}{7}$.