The measure of angle C is 50 Degeree
To find the measure of angle C in triangle ABC, you can use the Law of Cosines, which relates the lengths of the sides of a triangle to the cosine of one of its angles.
The Law of Cosines is expressed as:
![\[ c^2 = a^2 + b^2 - 2ab \cos(C) \]](https://img.qammunity.org/2021/formulas/mathematics/college/ilo8v6wjvtekbfq76lbgiem5twpak224im.png)
In this formula:
- c is the length of the side opposite angle C (BC in this case).
- a and b are the lengths of the other two sides (AB and AC, respectively).
- C is the measure of angle C.
Given the lengths:
- a = 6
- b = 7.5
- c = 6.5
Substitute these values into the Law of Cosines:
![\[ 6.5^2 = 6^2 + 7.5^2 - 2 \cdot 6 \cdot 7.5 \cos(C) \]](https://img.qammunity.org/2021/formulas/mathematics/college/o23ysq0djo4bo3cy91jwfe6fdas88unob2.png)
Now, solve for cos(C):
![\[ 42.25 = 36 + 56.25 - 90 \cos(C) \]](https://img.qammunity.org/2021/formulas/mathematics/college/qcyfwitxyjjo3juqf5xul0k7dymqw227iu.png)
![\[ c^2 = a^2 + b^2 - 2ab \cos(C) \]](https://img.qammunity.org/2021/formulas/mathematics/college/ilo8v6wjvtekbfq76lbgiem5twpak224im.png)
![\[ 90 \cos(C) = 56.25 - 36 + 42.25 \]](https://img.qammunity.org/2021/formulas/mathematics/college/h90qntkn89t4meecxg9a1pgt0nu15ighs5.png)
![\[ 90 \cos(C) = 62.5 \]](https://img.qammunity.org/2021/formulas/mathematics/college/t6oohqxk2ph3y2uoqarrxev5t3g1rexbei.png)
![\[ \cos(C) = (62.5)/(90) \]\\ \cos(C) \approx 0.694](https://img.qammunity.org/2021/formulas/mathematics/college/8hwwskmebkc8ywrr6lysldqyx0jp5zvpt4.png)
Now, find the angle C by taking the inverse cosine (cos⁻¹) of 0.694:
![\[ C \approx \cos^(-1)(0.694) \]](https://img.qammunity.org/2021/formulas/mathematics/college/ten4xd3u609mk3x65ixb24f5suqd94u31k.png)
Using a calculator, you find that C is 50 degrees.
The probable question may be:
In triangle ABC Side Ab=6, BC=6.5,AC=7.5 What is the measure of angle C?
A. 50 degree
B. 60 degree
C. 77 degree
D. 82 degree