We see a right triangle here.
Use the Pythagorean Theorem:
a^2+b^2=c^2
a & b=legs
c=hypotenuse
a^2+15^2=20^2
a^2+225=400
a^2=175
a=13.2287565553
a=13.2
The missing side is 13.2cm
The answer is B. Adjacent angles. They both have a meeting point and don't overlap.
The answer isn't A. because both angles don't add up to 90°.
The answer isn't C. because both angles aren't 90°.
The answer isn't D. because both angles don't add up to 180°.
Hope this helps! :)
\(^ ◇^)/
The answer is 280 degrees.
The triangle sum theorem says all 3 interior angles must equal 180 degrees.
so, 43 + 35 = 78. [ 180 - 78 = 102 degrees for the missing angles shared by the 2 triangles.
102 + 18 = 120. [180 - 120 = 60}
leaving the measure of Angle A as 60 degrees.
