Q101 of 113 Page 128

In Fig. 5.54, if l ||m, find the values of a and b.

∠ x = 180⁰-132⁰ = 48⁰(Forms a linear pair)

∠a = 180⁰-(65⁰ + 48⁰) = 67⁰ (Interior angles of a triangle are supplementary)

∠a, ∠b and ∠y are supplementary

∠ y = 65⁰ (Corresponding angle)

∠b = 180⁰-(67⁰ + 65⁰) = 48⁰

∠a = 67⁰, ∠b = 48⁰

In Fig. 5.52, AE || GF || BD, AB || CG || DF and ∠CHE = 120°. Find ∠ABC and ∠CDE.

100

In Fig. 5.53, find the value of ∠BOC, if points A, O and B are collinear.

102

In Fig. 5.55, l ||m and a line t intersects these lines at P and Q, respectively. Find the sum 2a + b.

103

In Fig. 5.56, QP || RS. Find the values of a and b.