Question

11. If the semi-perimeter of an equilateral triangle is 28√3 cm, then area of
equilateral triangle is ..... .... cm
icocolor richt angled triangle of equal side 30cm is given as​

Answer 1

semi-perimeter of an equilateral triangle : 3a / 2

3a/2 = 28√3 cm

a = 28√3 * 2/3

= 56√3 /3

area = √3/4 $a^{2}$

= √3/4 (56√3 /3 )²

=√3/4 (56² × (√3)² /3² )

= √3/4 (3136 × 3 / 9)

= √3 × 3136 × 3 /4 × 9

=  261.3 √3