Answer:
- angles: 31.42°, 31.42°, 117.16°
- legs: 23.79 m
Step-by-step explanation:
The base angles can be found from the definition of the tangent function:
tan(base angle) = height/(half-base length)
base angle = arctan(12.4/20.3) ≈ 31.418°
Then the apex angle is double the complement of this:
apex angle = 2(90° -31.418°) ≈ 117.164°
The base angles are 31.42°, and the apex angle is 117.16°.
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The leg lengths can be computed from the Pythagorean theorem applied to the altitude and the half-base length.
leg length = √(12.4² +20.3²) = √565.85 ≈ 23.789 . . . . meters
The length of the legs is about 23.79 m.