Question

Find the measure of an angle if it is 15° less than four times its complement​

Answer 1

Hii Mate, Thanks for asking this question .

Here is Your Answer,

Let the unknown no. be x

Its complement will be 90 - x

A/Q :-   x + 15 = 4(90 - x)

=>  x + 15 = 360 - 4x

=> 5x = 360 - 15

=> 5x = 5 ( 72 - 3)

=> x = 69

Another angle will be 90 - 69 = 21 Degree(ans)

Complementary angle

means whose sum is 90

degree while

supplementary angle

means a pair of angle

whose sum is 180 degree.

VERIFICATION :-

Put value of X in both LHS and RHS
69 + 15 = (90-69)4

=> 84 = 21 * 4

=> 84 = 84

so, our answer is correct !

HOPE IT HELPS YOU A LOT.....

Answer 2

Answer :

Let the number be 'x'.

It's compliment is 90° - x

According To Question :-

x = 4 (90° - x) - 15°

x = 360  - 4x - 15

x + 4x = 345

5x = 345

x = $\dfrac{345}{5}$

x = 69°

So, the measure of an angle is 69°.

The measure of another angle is (90 - 69) = 21°

VERIFICATION :

x = 4 (90 - x) - 15

Put x = 69°

69 = 4 (21) - 15

69 = 84 - 15

69 = 69

HENCE, IT IS VERIFIED..!

So, the measure of an angle is 69°.