Q. 14

# If every side of a triangle is doubled, then increase in the area of the triangle is

A. 100 %

B. 200%

C. 300%

D. 400%

Answer :

Let the sides of triangle are a, b, c

When a, b and c are the sides of triangle and s is the semi-perimeter, then its area is given by:

A = where [Heron’s Formula]

A’ = where [Heron’s Formula]

When each side of triangle is doubled

= = 2

A’ =

A’ = = 4= 4A

Increase in area = 4A-A = 3A

Percentage increase in area = = = 300%

Rate this question :

Find the area of an equilateral triangle having each side 6cm.

RS Aggarwal & V Aggarwal - MathematicsEach side of an equilateral triangle measures 8 cm. The area of the triangle is

RS Aggarwal & V Aggarwal - MathematicsA kite in the shape of a square with each diagonal 32 cm and having a tail in the shape of an isosceles triangle of base 8cm and each side 6cm, is made of three different shades as shown in the figure. How much paper of each shade has been used in it?

[Given : = 2.24]

RS Aggarwal & V Aggarwal - Mathematics

The sides of a triangle are 35 cm, 54 cm and 61 cm, respectively. The length of its longest altitude

NCERT Mathematics ExemplarThe sides of a quadrilateral, taken in order are 5, 12, 14 and 15 metres respectively, and the angle contained by the first two sides is a right angle. Find its area.

RD Sharma - MathematicsEach side of an equilateral triangle is 8 cm. Its altitude is

RS Aggarwal & V Aggarwal - MathematicsThe question consists of two statements namely, Assertion (a) and Reason (R). Please select the correct answer.

If the base of an isosceles triangle is 6cm and its perimeter is 16cm, then its area is 12cm^{2}.

The perimeter of an isosceles right- angled triangle having a as each of the equal sides is

RS Aggarwal & V Aggarwal - Mathematics