The base of an isosceles triangle is 42 feet long The altitude to the base is 70 feet long What is the measure of a base angle to the nearest degree?

Call the angle v: tan v = opp/ adj = 70/21 = 3.33; tan 73 = 3.26, tan 74 = 3.48

so 73 degrees is nearest.

Check: sin73 = opp/hyp so hyp is 70/sin 73 = 70/0.956 = 73.22.

Now use Pythagoras: does 73.22 squared equal 70 squared plus 21 squared?

In whole numbers 5329 = 4900 + 441? Not quite, but good enough for Wiki!