Question

[a] Neha decided to put up a soft board in her classroom. The length and breadth of the
board are 1 cm and b cm respectively.

(i) She decided to frame the board using a thick ribbon.
If 35 cm extra ribbon was required to frame it completely, what is the length (in cm) of the ribbon?

(ii) What will be the expenditure for making 50 such board:
if the carpenter charges Rs.z per board?
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Answer 1

Step-by-step explanation:

Since AB || CD and BC is a transversal.

So, ∠BCD = ∠ABC = xo     [Alternate angles]

As BC || ED and CD is a transversal.

∠BCD + ∠EDC = 180o

⇒ ∠BCD + 75o =180o

⇒ ∠BCD = 180o – 75o = 105o

∠ABC = 105o                 [since ∠BCD = ∠ABC]

∴ xo = ∠ABC = 105o

Hence, x = 105.