In Fig. 5.29, PQ||RS and a : b = 3 : 2. Then, f is equal to
a. 36°
b. 108°
c. 72°
d. 144°

Solution:

Given, PQ||RS and a : b = 3 : 2.

We have to find the value of f.

Since, a : b = 3 : 2

Let a = 3x and b = 2x

We know that the sum of a linear pair of angles is always equal to 180 degrees.

So, a + b = 180°

3x + 2x = 180°

5x = 180°

x = 180°/5

x = 36°

Now, a = 3(36°) = 108°

b = 2(36°) = 72°

If two parallel lines are intersected by a transversal, each pair of corresponding angles is equal.

From the figure,

Corresponding angles, f = a

So, f = 108°

Therefore, the value of f is 108°.

✦ Try This: In Figure, PQ||RS and a : b = 3 : 5. Then, h is equal to

☛ Also Check: NCERT Solutions for Class 7 Maths Chapter 5

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NCERT Exemplar Class 7 Maths Chapter 5 Problem 36

In Fig. 5.29, PQ||RS and a : b = 3 : 2. Then, f is equal to: a. 36°, b. 108°, c. 72°, d. 144°

Summary:

In Fig. 5.29, PQ||RS and a : b = 3 : 2. Then, f is equal to 108°

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☛ Related Questions:

• In Fig. 5.30, line l intersects two parallel lines PQ and RS. Then, which one of the following is no . . . .
• In Fig. 5.30, which one of the following is not true? a. ∠1 + ∠5 = 180°, b. ∠2 + ∠5 = 180°, c. ∠3 + . . . .
• In Fig. 5.30, which of the following is true? a. ∠1 = ∠5, b. ∠4 = ∠8, c. ∠5 = ∠8, d. ∠3 = ∠7