Which relationship in the triangle must be true? 8 b B 3 O sin(B) = sin(A) O sin(B) = cos(90 – B) O cos(B) = sin(180 – B) Orcos(B) = cos(A)​

Question

Which relationship in the triangle must be true? 8 b B 3 O sin(B) = sin(A) O sin(B) = cos(90 – B) O cos(B) = sin(180 – B) Orcos(B) = cos(A)​

in progress 0
Khoii Minh 5 years 2021-08-19T18:30:23+00:00 1 Answers 13 views 0

Answers ( )

  1. thugiang
    0
    2021-08-19T18:31:49+00:00
    Reply

    we know that

    In the right triangle ABC

    m∠A+m∠B=90 degrees——–> by complementary angles

    m∠A= 90 degrees -m∠B ——–> equation 1

    so

    sin (B)=b/c

    cos (A)= b/c

    sin (B)= cos (A)——–>equation 2

    substitute equation 1 in equation 2

    sin (B) = cos (90- B)

    herefore

    the answer is the option

    sin(B) = cos(90 – B)

Leave an answer

Browse

Giải phương trình 1 ẩn: x + 2 - 2(x + 1) = -x . Hỏi x = ? ( )