18. 3b° Pada gambar di atas, garis PQ Il RS. Nilai a + b C. 40 D. 75 A. 15 B. 25

18)
3b + 105* = 180*
3b = 180* - 105*
3b = 75*
b = 75* ÷ 3
b = 25*

5a = 3b
5a = 75*
a = 75* ÷ 5
a = 15*

Nilai a + b = 15* + 25* = 40* (jawaban C)