Page 259 - Start Up Mathematics_7

let’s evaluate

1. Calculate the area and perimeter of the shaded part of the given figure.
2. Find the area of the shaded region in the following figure. 14 cm
(Take π = 22 )
7
14 cm

6 cm 8 cm

9 cm
10 cm

P
7 cm Q

3. Calculate the area of regions marked P, Q and R in the
given rectangle. Area R
25 cm 2

4. The area of a triangle is equal to that of a square whose each side measures 70 cm. Find the
side of the triangle in metres, corresponding to the altitude measuring 35 cm.

Thinking Skills

1. Find the area of the shaded region in the figure given alongside.

2. The area of a rhombus is equal to that of a triangle whose side and
the corresponding altitude are 24 cm and 15 cm respectively. If one 28 cm
of the diagonals of the rhombus is 18 cm, find the other.
3. The floor of a hall which is 7.2 m long and 5.8 m wide is to be 8 cm
constructed using square tiles measuring 20 cm × 20 cm. Find the
number of tiles required to cover the floor. Also find the cost of the
tiles at the rate of ` 276 per dozen.

4. Find the area of the shaded portion in the following figures. Are these areas equal? Why?

14 cm 14 cm 14 cm

24 cm 24 cm 24 cm
(a) (b) (c)

5. A pulley cabin car ferries tourists on a ropeway from the base
to the hill top which is 6.28 km away. The rope loops around a
giant wheel that is 5 m in diameter. How many revolutions must
the giant wheel make to get the tourist on top?

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