The ratio of measures of two complementary angles is 4 to 5. The smallest measure is increased by 10%. By what percent must the larger measure be decreased so that the two angles remain complementary?

Respuesta :

Answer: The larger measure be decreased by 8% so that the two angles remain complementary .

Step-by-step explanation:

Given : The ratio of measures of two complementary angles is 4 to 5.

Let the complementary angles are  4x and 5x  ( indegrees) .

Since the sum of complementary angle is 90°.

Then,  4x+5x =90

9x=90

x= 10   [Divide both sides by 9]

Then , first angle = 4 (10)=40 °

Seconds angle = 5(10) = 50°

Smallest measure = 40°

The smallest measure is increased by 10%. , new angle = 40°+ 10% of 40°

= 40°+ (0.10)(40°)

= 40°+ 4°= 44°

Complement of 44° = 90°-44° = 46 °

Decrease in  larger angle = 50°- 46° = 4°

Percent decrease in  larger angle = [tex]\dfrac{\text{New angle}}{\text{Original angle}}\times100[/tex]

[tex]\dfrac{4}{50}\times100=8\%[/tex]

Hence, the larger measure be decreased by 8% so that the two angles remain complementary .