a. Find the length of the midsegment of an equilateral triangle with side lengths of 12.5 cm.


b. Given that UT is the perpendicular bisector of AB, where T is on AB, find the length of AT given AT = 3x + 6 and TB = 42 - x.

c. Given angle ABC has angle bisector BD, where AB = CB, find the value of x if AD = 5x + 10 and DC = 28 - x.

You try first

First one is trivial though. Inside top triangle is also equilateral and all its sides are 12.5 / 2

we did one virtually the same as this b one a few minutes ago

a. To find the length of the midsegment of an equilateral triangle, we know that it will be half the length of one side.

Therefore, the length of the midsegment is (1/2) * 12.5 cm = 6.25 cm.

b. Since UT is the perpendicular bisector of AB, it divides AB into two equal parts. This means that AT is equal to TB.
Therefore, we can set up the equation: 3x + 6 = 42 - x.
Simplifying the equation, we get: 4x = 36.
Dividing both sides by 4, we find: x = 9.
Substituting the value of x back into the expression for AT, we get: AT = 3(9) + 6 = 33.

c. The angle bisector BD divides angle ABC into two equal parts. This means that AD is equal to DC.
Therefore, we can set up the equation: 5x + 10 = 28 - x.
Simplifying the equation, we get: 6x = 18.
Dividing both sides by 6, we find: x = 3.
Substituting the value of x back into the expression for AD, we get: AD = 5(3) + 10 = 25.

a. To find the length of the midsegment of an equilateral triangle, we can use the fact that the midsegment is equal to half the length of one side of the equilateral triangle.

In this case, the side length of the equilateral triangle is given as 12.5 cm. Therefore, the length of the midsegment would be half of 12.5 cm, which is:

Midsegment length = 12.5 cm / 2 = 6.25 cm

So, the length of the midsegment of the equilateral triangle is 6.25 cm.

b. In order to find the length of AT, we need to find the value of x. From the given information, we know that UT is the perpendicular bisector of AB, which means that AT and TB are equal in length.

We are also given the expressions for AT and TB:
AT = 3x + 6
TB = 42 - x

Since AT and TB are equal in length, we can set up an equation:
AT = TB

Substituting the given expressions, we get:
3x + 6 = 42 - x

Solving this equation will give us the value of x. Once we find x, we can substitute it back into the expression for AT to find its length.

c. In order to find the value of x, we can use the angle bisector theorem. According to this theorem, the ratio of the two segments, AD and DC, created by the angle bisector BD is equal to the ratio of the lengths of the two sides opposite to the angle.

From the given information, we have:
AB = CB

Using the angle bisector theorem, we can set up an equation:
AD/DC = AB/CB

Substituting the given expressions, we get:
(5x + 10)/(28 - x) = AB/CB

Since AB = CB, we can simplify the equation to:
(5x + 10)/(28 - x) = 1

Solving this equation will give us the value of x. Once we find x, we can substitute it back into the expression for AD to find its length.