Hey there! We receieved your request
Stay Tuned as we are going to contact you within 1 Hour
One of our academic counsellors will contact you within 1 working day.
Click to Chat
1800-5470-145
+91 7353221155
Use Coupon: CART20 and get 20% off on all online Study Material
Complete Your Registration (Step 2 of 2 )
Sit and relax as our customer representative will contact you within 1 business day
OTP to be sent to Change
It is the outside boundary of any closed shape. To find the perimeter we need to add all the sides of the given shape.
The perimeter of a rectangle is the sum of its all sides. Its unit is same as of its length.
Perimeter = 3 + 7 + 3 + 7 cm
Perimeter of rectangle = 20 cm
Area of any closed figure is the surface enclosed by the perimeter. Its unit is square of the unit of the length.
The general formula to find the area of a triangle, if the height is given, is
If we have to find the area of a right-angled triangle then we can use the above formula directly by taking the two sides having the right angle one as the base and one as height.
Here base = 3 cm and height = 4 cm
Area of triangle = 1/2 × 3 × 4
= 6 cm 2
Remark: If you take base as 4 cm and height as 3 cm then also the area of the triangle will remain the same.
If all the three sides are equal then it is said to be an equilateral triangle.
In the equilateral triangle, first, we need to find the height by making the median of the triangle.
Here the equilateral triangle has three equal sides i.e. 10 cm.
If we take the midpoint of BC then it will divide the triangle into two right angle triangle.
Now we can use the Pythagoras theorem to find the height of the triangle.
AB2 = AD2 + BD2
(10)2 = AD2 + (5)2
AD2 = (10)2 – (5)2
AD2 = 100 - 25 = 75
AD = 5√3
Now we can find the area of triangle by
Area of triangle = 1/2 × base × height
= 1/2 × 10 × 5√3
25√3 cm2
In the isosceles triangle also we need to find the height of the triangle then calculate the area of the triangle.
Here,
The formula of area of a triangle is given by heron and it is also called Hero’s Formula.
where a, b and c are the sides of the triangle and s is the semiperimeter
Generally, this formula is used when the height of the triangle is not possible to find or you can say if the triangle is a scalene triangle.
Here the sides of triangle are
AB = 12 cm
BC = 14 cm
AC = 6 cm
If we know the sides and one diagonal of the quadrilateral then we can find its area by using the Heron's formula.
Find the area of the quadrilateral if its sides and the diagonal are given as follows.
Given, the sides of the quadrilateral
AB = 9 cm
BC = 40 cm
DC = 28 cm
AD = 15 cm
Diagonal is AC = 41 cm
Here, ∆ABC is a right angle triangle, so its area will be
Area of Quadrilateral ABCD = Area of ∆ABC + Area of ∆ADC
= 180 cm2 + 126 cm2
= 306 cm2
Get your questions answered by the expert for free
You will get reply from our expert in sometime.
We will notify you when Our expert answers your question. To View your Question
Revision Notes on Probability Probability...
Revision Notes on Areas of Parallelograms and...
Statistics CBSE Class 9 Science Revision Notes...
Revision Notes on Number Systems Introduction to...
Revision Notes on Coordinate Geometry Cartesian...
Revision Notes on Lines and Angles Basic terms and...
Revision Notes on Circles Introduction to Circles...
Revision Notes on Triangles Triangle A closed...
Revision Notes on Constructions Introduction to...
Revision Notes on Linear Equations in Two...
Revision Notes on Polynomials Polynomial...
Revision Notes on Surface Areas and Volumes Plane...
Revision Notes on Introduction to Euclid’s...
Revision Notes on Quadrilaterals Quadrilateral Any...