Question

#4 - find the exact value of x

Answer 1

x= 5.656854

We show the first 6 decimal units if there is no metric being asked ie) centimetres or millimetres

x = a

a² = c ² - b ²

a² = 9² - 7²

√32 = √81 -√49

a² = √32 = 5.656854

Explanation:

Have attached picture 7 that i promised from last question.

Also

Picture 8

= The angle at the centre is double the angle at the circumference.

Angle VWY = 1/2 of angle VOY = 1/2 x 180.

Picture 9 +10 ignore they are just for you to recognize 90 degree right angles so it can help you find x on tests/exams etc..

Picture 11 +12 are together the last ones ; if of interest is the hardest one.

Proof

Let angle CDE = x and angle EFC = y.

The angle at the centre is double the angle at the circumference.

Angle COE = 2y and the reflex angle COE = 2x.

Angles around a point add up to 360°.

2y + 2x = 360

2y/2+ 2x/2 = 360°/2

So y + x = 180°

Answer 2

5.7 or 6

Explanation:

Using Pythagoras theorem

Hypotenuse²= opposite²+adjacent²

Hypotenuse=9

Opposite =7

Adjacent =x

So

9²=7²+x²

81=49+x²

81-49=x²

32=x²

√32=√x²

5.7=x or approximately 6