Question

Calculate the area of an equilateral triangle whose height is 20 cm. Find the area of triangle whose sides are 17 cm 8 cm and 15 cm​

Answer 1

Given

Height of equilateral triangle (h) = 20 cm

Given sides of triangle = 17 cm . 8 cm . 15 cm

Area of an equilateral triangle with height (h) = h2/√3

∴ Area of equilateral triangle = (20 × 20)/√3

Area of equilateral triangle = 230.940 sq.cm

According to the Pythagoras theorem

(15)2 + (8)2 = (17)2

Since it is a right angle triangle

∴ Area of a triangle (A) = (1/2) ×b ×h

A = 0.5 × 15 × 8

A = 60 sq.cm

Answer 2

Answer:

Given height of equilateral triangle = 20 cm

Area of equilateral triangle with

height 'h' =

3

h

2

∴ Area of equilateral triangle =

3

(20)

2

=

3

400

×

3

3

=

3

400

3

sq. cm

Given sides of triangle

17 cm . 8 cm . 15 cm

By Pythagorous theorem

(15)

2

+(8)

2

=(17)

2

It is a right angled triangle

∴ Area of triangle =

2

1

×b×h

=

2

1

×15×8

= 60 sq cm

this is your answer ✔️