7th Grade > Mathematics
AREA AND PERIMETER MCQs
Perimeter And Area
:
B
Let ABCD be the square park and the region shaded in green be the path.
Here, side length of the outer square, AB = 11 m (given)
and the path is 2 m wide.
⇒ Side length of the inner square, HG
= 11 - 2 - 2 = 7 m
We know that area of a square = side2
⇒ Area of the path = Area of the outer square - Area of the inner square
=112−72=121−49=72 m2
:
A
EF divides the rectangle ABCD into two trapeziums.
Area of trapezium ABFE
=12×(Sum of parallel sides)×(Distance between them
=12×(AE+BF)×AB
=12×(1+2)×4
=12×3×4=6 cm2
Area of trapezium CDEF =12×(FC+ED)×CD
=12×(1+2)×4
=12×3×4=6 cm2
Area of both the trapeziums are equal.
∴ EF divides the rectangle ABCD in two equal parts and the area of both the parts are 6 cm2.
:
Area of the two semi-circles = 12(π×r2)+12(π×r2)=π×r2=227×7×7=154cm2
Area of rectangular part = length × breadth = 10 ×14 = 140 cm2
Total area = Area of the two semi-circles + Area of the rectangle = 154+140 = 294 cm2.
:
A
Given: The metal sheet in the form of a square of side 5 m.
The area of a square of side 'a' is given by a2.
So, area of the sheet =52=25 m2
:
C
Total cost of laying bricks in the park = Area of the park x rate
Area of a the park = (7 x 7) m2
= 49 m2
Cost = 49 m2 x ( ₹ 10) / m2
= ₹ 490
:
Area of parallelogram = b x h = 48 sq m.
:
B
The circumference of the tyre = 2πr (Distance travelled in each rotation)
Total Distance = Distance covered in 1 rotation x Number of rotations
⇒0.396=2×227×r×300
⇒r=0.396×72×22×300
Hence r = 0.00021 km or 21 cm.
:
B
When a circular disc is cut into four equal parts, the perimeter of each part is more than 2πr4. This is because the length of two radii are also added to the perimeter in each part.
Perimeter of each part = 2πr4+ r + r
= πr2 + 2r
= 22×77×2 + 2r
= 11+2×7
= 11 + 14
= 25 cm
:
B
Here we have two figures: a square of side 7 cm and a circle of diameter 7 cm, or radius 72 cm
Area of the shaded portion = Area of the square – Area of the circle
= a2–πr2 (where a is the side of the square and r is the radius of the circle)
= 72–227×72×72
= 49 – 38.5
= 10.5 cm2
:
Result : 1 Mark
Let the square given be of side A cm.
Perimeter of the square whose side is A cm is 4 × A
Perimeter of the given square
= 4 × 10
= 40 m
= 4000 cm