## points of sides AB and AC of / ABC, 7. In Fig. 13.28, D and E are the mid- Fig 13.27 is a the such that DE || BC. W

Question

points of sides AB and AC of / ABC,

7. In Fig. 13.28, D and E are the mid-

Fig 13.27

is a

the

such that DE || BC. What is

quadrilateral BCED called?

Fig. 13.28

ed

8. The measure of one angle of a parallelogram is 70″, What are the measures

of the remaining angles?

2

9. Two adjacent angles of a parallelogram are equal. What is the measure of

each angle?

(Hint : Sum of adjacent angles is 180)

w

10. Two adjacent angles of a parallelogram are in the ratio 2 : 3. Find the

measures of all the angles.

(Hint: Sum of adjacent angles is 180°)

in progress
0

Math
4 weeks
2021-11-06T08:46:12+00:00
2021-11-06T08:46:12+00:00 1 Answer
0 views
0
## Answers ( )

Answer:In parallelogram ABCD, ∠A and ∠B are adjacent angles supplementary to each other.

Thus, we have:

∠A + ∠B = 180°

Also,

∠A = x° and ∠B = (3x + 20)°

⇒ x° + 3x° + 20° = 180°

⇒ 4x° + 20° = 180°

⇒ 4x° = 160°

⇒ x° = 40°

⇒ x = 40

We know that opposite angles of a parallelogram are congruent.

Thus, we have:

∠C = ∠A = x°

⇒∠C= 40°

∠D = ∠B

⇒ ∠D = 3x° + 20°

= 3(40°) + 20°120°

+ 20°

= 140°

∴∠D=140°