Question

Questions no. 8 plz help Ch 20 Area and Perimeter of Plane Figures I only need the area BC = 5cm and Perimeter = 36cm

Answer 1

in triangle DBC
1/2* base* height
1/2*5*12
30cm^2
triangle ABD
Use herons formula...
ie p=1side+2side+3side/2
$\sqrt{p(p - a)(p - b)(p - c)}$
above is herons formula...
therefore p= 10+12+8/2
=15
$\sqrt{15(15 - 10)(15 - 12)(15 - 8)}$
=39.6863