I am getting really weird results in my program the shows Projectiles using Direct_X. Basically when I set the angle to 37 degrees, the ball goes further than when I set the angle to 45 degrees, yet it should go furtherest with 45.

This is how I am working it out:

Code:
ball.movex = 50 * cos(angle*3.14159265/180);
ball.movey =  50 * sin(angle*3.14159265/180);

ball.movex *= 0.1;
ball.movey *= -0.1;

//then in the game loop

ball.x += ball.movex;
ball.y += ball.movey;

if (keep going...)
ball.movey -= 0.98;
I don't know what causes this error.