the area of a parallelogram is 560 sq.cm. The height is 70cm. The base will be?
pls answer me
Answers
Answer:
Question 1.
Find the area and perimeter of the following parallelograms.
Samacheer Kalvi 7th Maths Solutions Term 1 Chapter 2 Measurements Ex 2.1 1
Solution:
(i) Given base b = 11 cm ; height h = 3 cm
Area of the parallelogram = b × h sq. units = 11 × 3 cm2
= 33 cm2
Also perimeter of a parallelogram = Sum of 4 sides
= 11 cm + 4 cm + 11 cm + 4 cm = 30 cm
Area = 33 cm2; Perimeter = 30 cm.
(ii) Given base b = 7 cm
height h = 10 cm
Area of the parallelogram = b × h sq. units
= 7 × 10 cm2 = 70 cm2
Perimeter = Sum of four sides
= 13 cm + 7 cm + 13 cm + 7 cm = 40 cm
Area = 70 cm2, Perimeter = 40 cm
Question 2.
Find the missing values.
Samacheer Kalvi 7th Maths Solutions Term 1 Chapter 2 Measurements Ex 2.1 2
Solution:
(i) Given Base 6 = 18 cm ; Height h = 5 cm
Area of the parallelogram = b × h sq. units
= 18 × 5 cm2
= 90 cm2
(ii) Base b = 8m; Area of the parallelogram = 56 sq. m
b × h = 56
8 × A = 56
h = 568
h = 7 m
(iii) Given Height h = 17 mm
Area of the parallelogram = 221 sq. mm
b × h = 221
b × 17 = 221
b = 22117
b = 13 m
Tabulating the results, we get
Samacheer Kalvi 7th Maths Solutions Term 1 Chapter 2 Measurements Ex 2.1 3
Question 3.
Suresh on a parallelogram shaped trophy in a state level chess tournament. He knows that the area of the trophy is 735 sq. cm and its base is 21 cm. What is the height of that trophy?
Samacheer Kalvi 7th Maths Solutions Term 1 Chapter 2 Measurements Ex 2.1 4
Solution:
Given base 6 = 21 cm
Area of parallelogram = 735 sq. cm
b × h = 735
21 × h = 735
h = 73521
h = 35 cm
∴ Height of the trophy = 35 cm
SamacheerKalvi.Guru
Question 4.
Janaki has a piece of fabric in the shape of a parallelogram. Its height is 12 m and its base is 18 m. She cuts the fabric into four equal parallelograms by cutting the parallel sides through its mid-points. Find the area of each new parallelogram.
Solution:
Samacheer Kalvi 7th Maths Solutions Term 1 Chapter 2 Measurements Ex 2.1 5
Area of a parallelogram = (base × height) sq. units
Base length = 182 = 9 m
Height = 122 = 6 m
Area = 9 × 6 = 54 m2
Area of each parallelogram = 54 m2
Question 5.
A ground is in the shape of parallelogram. The height of the parallelogram is 14 metres and the corresponding base is 8 metres longer than its height. Find the cost of levelling the ground at the rate of ₹ 15 per sq. m.
Solution:
Samacheer Kalvi 7th Maths Solutions Term 1 Chapter 2 Measurements Ex 2.1 6
Height of the parallelogram h = 14 m
Base = 8 m longer than height
= (14 + 8) m = 22 m
Area of the parallelogram = (base × height) sq. units
= (22 × 14)m2 = 308 m2
Cost of levelling 1 m2 = ₹ 15
Cost of levelling 308 m2 = 308 × 15 = ₹ 4,620
Cost of levelling the ground = ₹ 4,620
Objective Type Questions
Question 6.
The perimeter of a parallelogram whose adjacent sides are 6 cm and 5 cm is
(i) 12 cm
(ii) 10 cm
(iii) 24 cm
(iv) 22 cm
Solution:
(iv) 22 cm
Hint:
= 2(6 + 5) = 2 × 11 = 22 cm
Question 7.
The area of parallelogram whose base 10 m and height 7 m is
(i) 70 sq.m
(ii) 35 sq.m
(iii) 7 sq.m
(iv) 10 sq.m
Solution:
(i) 70 sq. m
Hint: = base × height = 10m × 7m = 70 sq.m
Question 8.
The base of the parallelogram with area is 52 sq. cm and height 4 cm is
(i) 48 cm
(ii) 104 cm
(iii) 13 cm
(iv) 26 cm
Solution:
(iii) 13 cm
Hint:
Samacheer Kalvi 7th Maths Solutions Term 1 Chapter 2 Measurements Ex 2.1 7
Question 9.
What happens to the area of the parallelogram if the base is increased 2 times and the height is halved?
(i) Decreases to half
(ii) Remains the same
(iii) Increase by two times
(iv) None
Solution:
(ii) Remains the same
Hint:
Area = b × h sq. units
New base = 2 × old base
New height = 12 × old height
New Area = New base × New height = (2 × b)12 × h = bh = old Area.
SamacheerKalvi.Guru
Question 10.
In a parallelogram the base is three times its height. If the height is 8 cm then the area is
(i) 64 sq. cm
(ii) 192 sq. cm
(iii) 32 sq. cm
(iv) 72 sq. cm
Solutio
Answer:
8cm²
Step-by-step explanation:
Using the diagram we want to find the base, let the base be the letter x
x times 70 =560
÷70 ÷70
so we will then divide 70 from each side to get x by itself
then we get x=8
so the base is 8cm²
