Question

HELP PLEASE 98 points

Answer 1

Answer:

Given: ​ BD ​is an altitude of △ABC .

Prove: sinA/a=sinC/c

Triangle ABC with an altitude BD where D is on side AC. Side AC is also labeled as small b. Side AB is also labeled as small c. Side BC is also labeled as small a. Altitude BD is labeled as small h.

Statement Reason

​ BD is an altitude of △ABC .

Given △ABD ​ and ​ △CBD ​ are right triangles. (Definition of right triangle)

sinA=h/c and sinC=h/a

Cross multiplying, we have

csinA=h and asinC=h

(If a=b and a=c, then b=c)

csinA=asinC

csinA/ac=asinC/ac (Division Property of Equality)

sinA/a=sinC/c

This rule is known as the Sine Rule.