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1. Determine the measure of the unknown angles indicated by letters. Justify your answers with

the properties or theorems you used

1. Determine the measure of the unknown angles indicated by letters. Justify your-example-1
User Matthieu Charbonnier
by
2.9k points

1 Answer

28 votes
28 votes

Answer:

hello,

Explanation:

a)

In an isocele triangle, base's angles have the measure:

42+2a=180

2a=180-42

a=69(°)

b)

in a triangle, an external angle has for measure the sum of the angles not adjacents.

55+b=132

b=77 (°)

c)

in a quadrilater the sum of the (interior) angles is 2*180=360 degrees.

90+90+68+c=360

c=360-90-90-68

c=112 (°)

User Nicola Miotto
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