Question

Two adjacent sides of a parallelogram measure 15 cm and 20 cm while the diagonal opposite their common vertex measures 25 cm find the area of the parallelogram

Answer 1

by herons formula
s=15+20+25/2=60/2=30
$\sqrt{30(30 - 15)(30 - 20)(30 - 25)}$
$\sqrt{30 \times 15 \times 10 \times 5}$
$\sqrt{2 { }^{2} \times 3 {}^{2} \times 5 {}^{2} \times 5 {}^{2} }$
=2×3×5×5
=150cm^2
wkt a diagonal of a parallelogram divides it into two congruent triangles of equal area.
area of ||gm= 2(150cm^2)
are of ||gm=300cm^2