Question

In ∆ ABC, angle A=90° , BC=15cm, sin B=4/5. Calculate the perimeter of the triangle?
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Answer 1

Answer:

36cm

Step-by-step explanation:

sinB= 4/5

also, sin B= P/H

therefore,

4/5=AC/BC

4/5=AC/15

AC= (4*15)/5

AC=12cm

using Pythagoras theorem,

BC²=AC²+AB²

AB²=(15)²- (12)²

AB²= 225 - 144

AB=√81

AB=9cm

perimeter of∆ABC= AB + BC + AC

=9+15+12=36cm

Hope this helps you.