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4. The interior angles of a triangle are 60°, 45° and 75°. The shortest side is 10 cm less than the

longest side. Determine the perimeter of the triangle to the nearest cm.

User Memen
by
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1 Answer

5 votes

Answer:

Explanation:

The length of each side corresponds to the sizes of each angle respectively.

To determine the length of each side, we would apply sine rule which is expressed as

a/sinA = b/SinB = c/SinC

The diagram of the triangle is shown in the attached photo. The longest side is c. If the shortest side is 10 cm less than the longest side, it means that the length of the shortest side is c - 10

Therefore,

c/Sin75 = (c - 10)/Sin45

c/0.966 = (c - 10)/0.707

Cross multiplying, it becomes

c × 0.707 = 0.966(c - 10)

0.707c = 0.966c - 9.66

0.966c - 0.707c = 9.66

0.259c = 9.66

c = 9.66/0.259

c = 37.3 cm

The shortest side is

37.3 - 10 = 27.3 cm

Applying the sine rule again,

b/Sin60 = 37.3/Sin75

b/0.866 = 37.3/0.966

Cross multiplying, it becomes

0.966b = 0.866 × 37.3

b = 32.3018/0.966

b = 33.4 cm

The perimeter is

27.3 + 33.4 + 37.3 = 98 cm

4. The interior angles of a triangle are 60°, 45° and 75°. The shortest side is 10 cm-example-1
User Blachniet
by
5.3k points
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