a) Similar triangles have their three corresponding angles congruent to each other, while the ratio of their corresponding sides are proportional to each other.
Since ∆ABC ~ ∆GLJ, therefore,
<A = <G,
<B = <J
<C = <L
m<J = 100° (given)
Therefore,
m<B = m<J = 100°
m<B = 100°
b) m<A = m<G
m<A = 25° (given)
Therefore,
m<A = m<G = 25°
m<G = 25°
m<L = 180° - (m<J + m<G)
Substitute
m<L = 180° - (100° + 25°)
m<L = 55°
c) scale factor of smaller triangle to the larger = side length of smaller triangle / corresponding side length of bigger triangle
