Question

If ∠A and ∠B are two adjacent angles of a parallelogram. If ∠A = 60°, then ∠B = ?

Answer 1

Given

⭐∠A = 60⁰

⭐∠A and ∠B are adjacent angles

To find

⭐∠B = ?

${\underline{\tt{\purple{★solution⟹}}}}$

$\</strong><strong>s</strong><strong>m</strong><strong>a</strong><strong>l</strong><strong>l</strong><strong>\boxed{</strong><strong>⭐∠A = ∠C. </strong><strong>}$ (opp angles of parallelogram are equal)

⟹ ∠B + ∠C = 180⁰ ( co-interior angles)

⟹ ∠B + 50⁰ = 180⁰

⟹ ∠B. = 180⁰ - 60⁰

⟹ ∠B = $\small{\underline{\tt{\orange{120⁰}}}}$

Hope it helps.

Answer 2

$\sf\large\purple{Given⟹}$

ABCD is a parallelogram and $\tt ∠A=60°$

$\sf\large\green{Solution⟹}$

We know that opposites angles of a parallelogram are equal.

Therefore,

${\sf{\boxed{∠A=∠C=60°}}}$

${\sf {\underline{\boxed{Formula \to ∠A+∠B=180°}}}}$

$\sf\implies 60° +∠B=180°$

$\sf\implies ∠B=120°$

${\bold{\sf{\implies{\blue{ ∠B=∠D=120°}}}}}$ (opposite angles of parallelogram)