Question

Choose the correct alternative answer. 1. In ΔABC, ∠ A = 30° , ∠ B = 90°. If AC = 4 cm find the length of BC *

a) 2 cm

b) 4 cm

c) 8 cm

d) None of these
​

Answer 1

Step-by-step explanation:

∠ B = 90°.

then traingle ABC is right angle trriangle and

AC is hypotenuse

we know that sin thetha = perpendicular/hypotenuse

sin 30° = BC/AC

1/2. = BC/4

1/2 ×4 = BC

2 = BC

length of BC  = 2cm