Answer to Question #191649 in Geometry for Angelo

Question

If the sides of the parallelogram and an included angle are 6, 10 and 100 degrees respectively, find the length of the larger diagonal.

Answer 1

let a=6, b=10, diagonal =d

$d^2=a^2+b^2-2abcos100^o=6^2+10^2-2\times6\times 10 cos100^o$

$d^2=36+100+20.76=156.76$

$d=\sqrt{156.76}=12.52$