Question

Calculate the area of a rhombus with side length of 20cm and angles of 60°and 120°

Answer 1

Since one angle is 60°.

Therefore, one of the diagonal will divide the triangle into two equilateral triangles with side 20 cm.

In one equilateral triangle draw perpendicular.

Length of perpendicular=√20^2-10^2

=√300

=10√3 cm

Area of one triangle=base*height/2

=20*10√3/2

=100√3 cm^2

Area of rhombus=200√3 cm^2