Question

If 4 ;5 are two sides of a triangle and the included angle is 60 find its area

Answer 1

Answer:

5√3 cms^2

Step-by-step explanation:

in triangle ABC

let AB=4 CMS, BC=5CMS AND angle B=60°

draw AD perpendicular to BC

this implies angle ADB=90°

also angle BAD=30°

IN right angle ∆ ADB

sin60°=AD/AB

√3/2=AD/4

√3/2×4= AD

2√3=AD

CONSIDER AD=2√3 as height of ∆ABC

Area of∆ABC=1/2× base × height

Area of∆= 1/2×5×2√3

Area of∆=5√3 cms^2