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Help please i don't understand​

Help please i don't understand​-example-1

1 Answer

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○=> Solution (2) :

This triangle(Fig. 9.120) is a right angled triangle.

So, the three angles in this triangle are :

▪︎angle 90°, angle 63° and angle y.

Sum of all angles in a triangle = 180°

Which means :


= \tt90 + 63 + y = 180


= \tt153+ y= 180


= \tt \: y = 180 - 153


\hookrightarrow \color{plum}\tt angle \: y = 27°

Since the sum of all angles equals 180°[90+63+27=180] we can conclude that we have found out the correct measure of angle y.

▪︎Therefore, the measure of angle y = 27°

○=> Solution (3) :

The triangle in Fig. 9. 121 is a right angled triangle.

So, the angles in this triangle are :

▪︎angle 90°, angle 28.3° and angle z.

Sum of all angles in a triangle = 180°

Which means :


= \tt 90 + 28.3 + z = 180


= \tt118.3 + z = 180


= \tt z = 180 - 118.3


\hookrightarrow \color{plum} \tt \: angle \: z = 61.7°

Since the sum of all angles equals 180°[90+28.3+61.7=180°] we can conclude that we have found out the correct measure of angle z.

▪︎Therefore, the measure of angle z = 61.7°

○=> Solution (4) :

The triangle in Fig. 9. 122 is a right angled triangle.

So, the angles in this triangle are :

▪︎angle 90°, angle 45.8° and angle x.

Sum of all angles in triangle = 180°

Which means :


= \tt90 + 45.8 + x = 180


= \tt135.8 + x = 180


= \tt x = 180 - 135.8


\hookrightarrow \: \color{plum}\tt \: angle \: x = 44.2°

Since the sum of all angles equals 180°[90+45.8+44.2=180°] we can conclude that we have found out the correct measure of angle x.

▪︎Therefore, the measure of angle x = 44.2°

○=> Solution (5) :

The triangle in Fig. 9.123 is a right angled triangle.

So, the angles in this triangle are :

▪︎angle 90°, angle 35.7° and angle y.

Sum of all angles in a triangle = 180°

Which means :


= \tt90 + 35.7 + y = 180


= \tt 125.7 + y = 180


= \tt y = 180 - 125.7


\hookrightarrow \color{plum}\tt angle \: y = 54.3°

Since the sum of all angles equals 180°[90+35.7+54.3=180°] we can conclude that we have found out the correct measure of angle y.

▪︎Therefore, the measure of angle y = 54.3°

○=> Solution (6) :

No, angle x is not twice of angle y. As we know the value of angle x in fig. 9.122 is equal to 44.2°. And the value of angle y in fig. 9.123 is equal to 54.3°. Since the measure of angle x is lesser than angle y it cannot be twice as much as angle y.

Therefore, angle x is not twice as much as angle y since angle x < angle y.

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