Question

.▢ ABCD is a parallelogram.If <A=(6x +9)° and <D=(3x-18)° , then find the measures of < B and <C respectively. *​

Answer 1

Answer:

<B = 45°

<B = 45° <C = 135°

Step-by-step explanation:

Given : ◻ABCD

<A = <C

<B = <D ; Thus,

6x + 9° = <C

3x-18° = <B

To find the x:

<A + <B = 180° or <C + <D = 180°

6x+9° + 3x - 18° = 180°

9x° - 9° = 180°

9x = 180° + 9°

9x = 189

9x

x = 21°

The value of our x is 21.

To find the value of an angle, substitute the x:

<A/<C = 6x + 9°

<A/<C = 6(21°) + 9°

<A/<C = 126° + 9°

< A / <C = 135°

<B/<D = 3x-18°

<B/<D = 3(21°) -18°

<B/<D = 63° - 18°

<B/<D = 45°

Check:

<A/<C + <B/<D = 135° + 45° = 180° ✔