Question

the difference between the two acute angles of right angled right triangle is 2pi/5 radians.Find them in radians.

Answer 1

@ganeshie8

Answer 2

find in radians or degrees?

Answer 3

radians

Answer 4

@Qwertty123

Answer 5

Um I'm not sure sorry, I can only work out degrees sorry :(

Answer 6

The sum is 90 degrees and their difference is 2 pi/5 radians or 72 degrees. All you did was convert the difference to degrees.
A + B = 90
A - B = 72
2A = 162
A = 81
B = 90 - 81 =?

Answer 7

I didn't get you.

Answer 8

what is 90-81?

Answer 9

The right angle is 90 degree so shouldn't i convert it to radians?

Answer 10

90-81 = 9

Answer 11

whoops yes XD

Answer 12

how do I do that?

Answer 13

oh okay Radian measure of a central angle is defined as the ratio of the arc length to the length of the radius. This definition leads to the arc length formula: . Radians and degrees are connected by the relationship . If you wish to convert from degrees to radians, multiply the degree measure by...~ http://www.montereyinstitute.org/courses/DevelopmentalMath/TEXTGROUP-1-19_RESOURCE/U19_L2_T1_text_container.html

Answer 14

???

Answer 15

Is the final answer 90 and 10 rads?

Answer 16

no.
let the two angles be a and b.
All the angles in a triangle add up to π radians, so the two acute angles add up to π/2.
So one equation you can write is \[a+b=\frac{ \pi }{ 2 }\]
You're also given the difference, so another equation is\[a-b=\frac{ 2\pi }{ 5 }\]
Solve the system of equations for a and b

Answer 17

start by adding the equations together to eliminate b.

Answer 18

b gets cancelled and a is 81?

Answer 19

yes if you follow @Qwertty123's work, but there's no reason to convert anything to degrees since your answer has to be in radians.

You'd have to convert the 81 to radians

Answer 20

thats 90 rad?

Answer 21

Very well done! :3